World-wide incidence of Alphavirus: a bibliography

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AU - Barbosa JA, Rebello MA
TI - Prostaglandin A1 inhibits replication of Mayaro virus in Aedes albopictus cells.
SO - Brazilian Journal of Medical & Biological Research 1995 Jan;28(1):27-30
AB - Prostaglandin A1 (PGA1) reduced Mayaro virus replication in Aedes albopictus (mosquito) cells in culture. The highest nontoxic dose of PGA1, 7.5 microM, decreased virus production by 90%. In Mayaro virus-infected cells, PGA1 inhibited virus-specific protein synthesis. However, in mock-infected cells the presence of PGA1 stimulated the synthesis of several proteins with molecular masses of 70, 57 and 23 kDa, respectively. The data obtained from this study show that PGA1 plays a role in the metabolic regulation of Aedes albopictus cells, blocking the synthesis of Mayaro virus and inducing the synthesis of cellular polypeptides.

AU - Motta MC, Fournier MV, Carvalho MG
TI - Serum concentration and increased temperature alter Mayaro virus RNA and protein synthesis in Aedes albopictus (mosquito)-infected cells.
SO - Brazilian Journal of Medical & Biological Research 1995 Jan;28(1):18-26
AB - We have previously shown the inhibition of Mayaro virus multiplication in Aedes albopictus-infected cells maintained at a supraoptimal temperature for growth (37 degrees C) and a stimulation of virus production in response to high serum concentrations in the incubation medium. In the present study, we addressed the question of how the effect of continuous heat stress and high serum concentration soon after infection interfere with virus macromolecule synthesis. Cells maintained at 28 degrees C in the presence of 2% serum synthesized a viral genomic RNA of 12 kb and a subgenomic RNA of 5.2 kb 6 h postinfection. Analysis of the protein profile showed the presence of the viral nucleocapsid protein of 34 kDa (P34). However, if infected cells were maintained at 37 degrees C, a smear starting immediately below the 5.2-kb RNA was noticed and the viral P34 was not detected by SDS-PAGE. Addition of 10% serum to the growth medium of infected cells maintained at 37 degrees C results in a viral RNA profile and protein synthesis similar to those observed in cultures kept at 28 degrees C, i.e., the smear was not observed and the P34 protein was detected. The results suggest that the inhibition of virus multiplication by temperature may be related to the inhibition of viral nonstructural protein synthesis early during infection. The presence of high serum levels in the incubation medium protects macromolecule synthesis against heat stress.

AU - Weinstein P, Weinstein SR, Rowe RJ
TI - Transfusions: how many cases of Ross River virus infection do we cause? [letter].
SO - Medical Journal of Australia 1995 Sep 4;163(5):276

AU - Guy JS, Siopes TD, Barnes HJ, Smith LG, Emory WH
TI - Experimental transmission of eastern equine encephalitis virus and Highlands J virus via semen of infected tom turkeys.
SO - Avian Diseases 1995 Apr-Jun;39(2):337-42
AB - Tom turkeys were experimentally inoculated with eastern equine encephalitis (EEE) virus or Highlands J (HJ) virus; semen was examined for presence of virus and ability to transmit infection by artificial insemination. Mild depression and inappetence were observed in tom turkeys inoculated with either EEE virus or HJ virus. Toms were viremic on days 1-2 postinoculation (PI), and virus was shed in semen on days 1-5 PI. Semen collected from EEE-virus-inoculated or HJ-virus-inoculated toms on days 1-2 PI and inseminated into turkey breeder hens transmitted the infection. EEE virus was detected in one of 10 hens after insemination with semen from EEE-virus-inoculated toms, and HJ virus was detected in three of 10 hens after insemination with semen from HJ-virus-inoculated toms. These results indicate that semen is a potential vehicle for transmission of EEE virus and HJ virus.

AU - Neogi DK, Bhattacharya N, Mukherjee KK, Chakraborty MS, Banerjee P, Mitra K, Lahiri M, Chakravarti SK
TI - Serosurvey of chikungunya antibody in Calcutta metropolis.
SO - Journal of Communicable Diseases 1995 Mar;27(1):19-22
AB - Since its first isolation in Calcutta, in 1963, there have been many reports about epidemis of chikungunya virus infection in different parts of India. Calcutta experienced a concurrent epidemic of dengue and chikungunya between 1963 and 1965. But after that there is no report about any chikungunya infection in Calcutta. During routine investigations it is found that chikungunya antibody is on the wane. The present survey for chikungunya antibody showed only 4.37% (n = 17) seropositivity out of 389 sera tested. The highest (12.5%) seropositivity was observed in the age group of 51-55 years and no chikungunya antibody was detected in young and young adults. The findings suggest that chikungunya virus is disappearing from the Calcutta population.

AU - Ha DQ, Calisher CH, Tien PH, Karabatsos N, Gubler DJ
TI - Isolation of a newly recognized alphavirus from mosquitoes in Vietnam and evidence for human infection and disease.
SO - Am. J. Trop. Med. Hyg. 1995 Jul;53(1):100-4
AB - During studies of arboviral epidemiology in Vietnam, five virus isolates were recovered from Culex tritaeniorhynchus mosquitoes. Three of the five isolates were identified as strains of Japanese encephalitis virus, but the others, collected at Me Tri village, Hanoi, were shown to represent an alphavirus, for which we propose the name Me Tri virus. This newly recognized virus is most closely related to Semliki Forest virus. The two isolates appear to be antigenic subtypes of a single virus, and each was associated with central nervous system illnesses in children. Serologic surveys indicate widespread distribution of these viruses in both humans and livestock in Vietnam. We suggest that Me Tri virus is an etiologic agent of human disease in southeast Asia.

AU - McGill PE
TI - Viral infections: alpha-viral arthropathy. [Review]
SO - Baillieres Clinical Rheumatology 1995 Feb;9(1):145-50
AB - Six different mosquito-borne viruses (Chikungunya, O'nyong-nyong, Mayaro, Ross River, Sindbis and Barmah Forest) have been associated with arthritis in humans. These viruses are prevalent in the tropics and subtropics and they produce similar symptoms, consisting of fever, joint pains and rash. The symptoms are usually of short duration, around 1 week; complete recovery is the rule apart from exceptional cases of Chik infection. Precise diagnosis requires a serological service which is not available in many parts of the tropics these days. Treatment is symptomatic and there is no vaccine currently available. With an increasing number of visitors to the tropics being exposed to potential infection and with rapid air transport it is possible that visitors may return home during the viraemic incubation stage, infect the local mosquito populations and then develop clinical disease. [References: 31]

AU - Lindsay MD, Johansen CA, Smith DW, Wallace MJ, Mackenzie JS
TI - An outbreak of Barmah Forest virus disease in the south-west of Western Australia.
SO - Medical Journal of Australia 1995 Mar 20;162(6):291-4
AB - OBJECTIVES: To describe the first reported outbreak of Barmah Forest (BF) virus disease in the south-west of Western Australia. DESIGN: Case series correlated with results of arbovirus surveillance. All patients with clinically suspected Ross River (RR) virus infection were serologically tested for antibodies to BF and RR viruses. Home address and date of presentation of patients with serologically confirmed recent infection were recorded. Mosquitoes collected from the districts before and during the BF virus outbreak were identified to species level and tested for virus. RESULTS: Twenty-two cases of BF disease were reported from the region between August 1992 and March 1994. Most occurred in the Peel region in the spring and early summer of 1993. Eighteen isolates of BF virus were obtained from three different species of mosquito trapped between January and October 1993. Fifteen were from mosquitoes in the Peel region and a single isolate was from the Perth metropolitan area. No isolates were obtained from the region before 1993. RR virus was not isolated from mosquitoes trapped in the region during the BF virus outbreak. CONCLUSIONS: Most BF infections were acquired in the Peel region during spring and early summer of 1993. Aedes camptorhynchus mosquitoes were probably the main vectors. The lack of isolations from mosquitoes before 1993 suggests that the virus may have only recently been introduced (or reintroduced) to the region. It was transmitted under conditions that were apparently not conducive to transmission of RR virus.

AU - Trevett AJ, Sanders RC
TI - Arbovirus disease in Papua New Guinea. [Review]
SO - Papua New Guinea Medical Journal 1994 Jun;37(2):116-24
AB - It is clear that exposure to arthropod-borne viruses is common in the populations of both Papua New Guinea and Irian Jaya. Clinical disease resulting from these infections has been reported although the paucity of case reports and combined clinical experience suggest that it is rare. Dengue epidemics due to dengue-1 and dengue-2 have occurred and it is likely that dengue-3 is also present in the region. No cases of dengue haemorrhagic fever have been described. Murray Valley encephalitis, Ross River and antigenically related viruses are widespread in Papua New Guinea and Irian Jaya, particularly in the lowland and coastal areas. Antibodies to Japanese encephalitis virus have not been found in blood samples from Papua New Guinea or Irian Jaya. As Papua New Guinea is developed, new areas of the country are opened up and ecosystems are altered. It is important that physicians based in Papua New Guinea, and those who deal with patients living or working here, are aware of the arbovirus diseases which occur and the potential and preventable problems posed by them to both the individual and the community. [References: 40]

AU - Guy JS, Barnes HJ, Smith LG
TI - Experimental infection of young broiler chickens with eastern equine encephalitis virus and Highlands J virus.
SO - Avian Diseases 1994 Jul-Sep;38(3):572-82
AB - Two-week-old broiler chickens were experimentally infected with either eastern equine encephalitis (EEE) virus or Highland J (HJ) virus. Mortality rates were 24/30 (80%) in EEE-virus-inoculated chickens and 2/30 (7%) in HJ-virus-inoculated chickens. Chickens inoculated with EEE virus exhibited severe depression and somnolence on days 1-6 postexposure (PE), with 17/30 birds dying during this period. After day 6 PE, EEE-virus-inoculated chickens exhibited abdominal distention, depression, and growth retardation, and an additional seven chickens died. Pathologic changes in EE-virus-inoculated chickens dying on days 1-6 PE consisted of multifocal necrosis in the heart and liver, as well as lymphoid depletion and necrosis in the thymus, spleen, and bursa of Fabricius. Ascites, pericardial effusion, and right ventricular dilatation of the heart were the predominant lesions in chickens dying after day 6 PE. No clinical signs were observed in sham-inoculated controls or in most HJ-virus-inoculated chickens. Ascites, pericardial effusion, and multifocal myocardial necrosis were observed in 2/30 HJ-virus-inoculated chickens that died or were euthanatized after development of clinical signs. These findings indicate that both EEE virus and HJ virus are pathogenic for young chickens.

AU - Guy JS, Barnes HJ, Ficken MD, Smith LG, Emory WH, Wages DP
TI - Decreased egg production in turkeys experimentally infected with eastern equine encephalitis virus or Highlands J virus.
SO - Avian Diseases 1994 Jul-Sep;38(3):563-71
AB - Turkey breeder hens were experimentally infected with strains of eastern equine encephalitis (EEE) virus or Highlands J (HJ) virus previously isolated from turkey hens experiencing decreased egg production. Depression and inappetance were observed on day 1 postexposure (PE) in hens inoculated with either EEE virus or HJ virus, and egg production fell in each virus-inoculated group from approximately 75% to less than 20% within 2-3 days PE. Egg production remained depressed (less than 20%) for 15 days in EEE-virus-inoculated hens and for 7 days in HJ-virus-inoculated hens. EEE virus and HJ virus were recovered from various tissues on days 1-5 PE, and virus was detected in eggs laid on days 2-5 PE. The findings of this study confirm that EEE virus and HJ virus are potential causes of decreased egg production in turkey breeder hens.

AU - Sellner LN, Coelen RJ, Mackenzie JS
TI - Sensitive detection of Ross River virus--a one-tube nested RT-PCR.
SO - Journal of Virological Methods 1994 Aug;49(1):47-58
AB - A sensitive nested RT-PCR that can be carried out in a single tube is described. The sensitivity of this system was determined, and compared to that of a single round of PCR, and a single round of PCR followed by hybridisation with a radiolabelled oligonucleotide probe. We found that with the one-tube nested RT-PCR we were able to detect 0.1 pfu/ml of Ross River virus. The nested RT-PCR was 100-times more sensitive than a single round of RT-PCR followed by hybridisation, and 10,000-times more sensitive than a single round of RT-PCR alone. This system provides a sensitive detection of Ross River virus, and can be adapted for detection of RNA from any source. The test material is added to a single tube at the outset, and by subsequent addition of two sets of reagents, the entire nested RT-PCR can be carried out in the same tube. This system has maximum sensitivity, minimises risk of contamination, and is amenable to automation.

AU - Maguire T
TI - Do Ross River and dengue viruses pose a threat to New Zealand?.
SO - New Zealand Medical Journal 1994 Nov 9;107(989):448-50
AB - AIM. To determine the prevalence of antibodies to Ross River and dengue viruses in sera from New Zealand residents and travellers and to assess the potential of local mosquitoes to act as vectors of these viruses. METHOD. Serum specimens from several population groups were examined by haemagglutination-inhibition and neutralisation tests for antibodies to Ross River and dengue viruses between 1975 and 1993. During this period dengue was active in South East Asia, Australia and the Pacific, and a major epidemic of Ross River infection occurred in the Pacific. Two New Zealand mosquito species were tested for their ability to transmit by bite after they had been fed or injected with these viruses. RESULTS. Ten percent of 1869 sera from patients suspected of contracting dengue, and 43% of 183 patients suspected of contracting Ross River virus, while overseas, were antibody positive. Many patients showed antibody rises which indicated that they were probably viraemic on entry to this country. Dengue viruses were isolated in Dunedin from two patients with dengue haemorrhagic fever contracted overseas. Antibody studies of persons who had not travelled outside New Zealand provided no evidence of local transmission of these viruses. Two local mosquitoes, Aedes notoscriptus from the Auckland area, and Aedes australis from the Otago area, were able to transmit one or both these viruses under laboratory conditions. CONCLUSIONS. The serological studies showed that both Ross River and dengue viruses have probably been introduced into New Zealand by viraemic travellers on many occasions. Although some local mosquitoes can transmit these viruses in the laboratory, there is no evidence of local spread of virus from these imported cases. Changing environmental conditions such as global warming with concomitant effects on vector distribution, increasingly rapid air travel by viraemic persons and the accidental introduction of new vector mosquitoes, particularly Aedes albopictus, could pose a threat in view of the high percentage of New Zealand residents with no protective antibody.

AU - Peiris JS, Amerasinghe PH, Amerasinghe FP, Calisher CH, Perera LP, Arunagiri CK, Munasingha NB, Karunaratne SH
TI - Viruses isolated from mosquitoes collected in Sri Lanka.
SO - Am. J. Trop. Med. Hyg. 1994 Aug;51(2):154-61
AB - Attempts to isolate viruses from 178,181 unengorged female mosquitoes collected from different ecologic areas of Sri Lanka yielded 31 isolates: 17 of Japanese encephalitis (JE) virus, nine of Getah virus, three of a Batai-related bunyavirus, and two of Arkonam virus. Culex tritaeniorhynchus and Mansonia uniformis mosquitoes were found to carry JE virus in a dry zone nonepidemic area, and Cx. pseudovishnui was found to carry it in a wet zone nonepidemic area. Japanese encephalitis virus was isolated from Cx. tritaeniorhynchus, Cx. gelidus, Cx. fuscocephala, and Cx. whitmorei during a human epidemic in the dry zone. Getah virus was isolated from Cx. tritaeniorhynchus, Cx. gelidus, and Cx. fuscocephala collected in the vicinity of swine. Isolations of Getah, Arkonam, and Batai-related viruses from Sri Lanka are reported for the first time.

AU - Shortridge KF, Mason DK, Watkins KL, Aaskov JG
TI - Serological evidence for the transmission of Getah virus in Hong Kong.
SO - Veterinary Record 1994 May 14;134(20):527-8

AU - Eleazer TH, Hill JE
TI - Highlands J virus-associated mortality in chukar partridges.
SO - Journal of Veterinary Diagnostic Investigation 1994 Jan;6(1):98-9

AU - Anonymous
TI - Ross River virus infection.
SO - Weekly Epidemiological Record 1994 Apr 1;69(13):98-9

AU - Weinstein P, Worswick D, Macintyre A, Cameron S
TI - Human sentinels for arbovirus surveillance and regional risk classification in South Australia.
SO - Medical Journal of Australia 1994 Apr 18;160(8):494-9
AB - OBJECTIVES: To assess the use of human sentinels to monitor arbovirus activity in South Australia and to use age-specific seroprevalence data from the same sentinels to classify regions according to risk from Ross River virus (RRV). METHODS: Between 1 January 1992 and 15 August 1992, 4776 serum samples were obtained from Red Cross blood donors in the State. All sera were tested for the presence of total antibody (IgA, IgG and IgM) by indirect enzyme immunoassay. To test for recent infection, positive sera were further tested for IgA and IgM specific antibody to Ross River virus with a view to initiating public health interventions if necessary. The age, sex and postcode of residence of each donor were also recorded for seroepidemiological studies. RESULTS: Of the 4776 sera, 2952 were tested to the end of May (the end of the arbovirus season in South Australia). There was evidence of RRV infection in 248 sera (8.4%) but none had serological markers consistent with recent infection. The arbovirus season was considered non-epidemic, and no reactive public health interventions were introduced. Analysis of age-specific seroprevalence by post-code in the full bank of 4776 sera indicated that the Riverland is endemic for RRV, the Murray Mallee and Upper South East epidemic for RRV, and the remaining regions of the State at variable risk, depending on their proximity to these regions. CONCLUSIONS: The ongoing use of human sentinels is a new public health surveillance system for this disease. In the first year of operation of this surveillance system, a suboptimal number of sera was collected from some areas, and sera were tested only for RRV. However, the number of sera tested could easily be increased, as could the range of arboviruses covered by the testing.

AU - Levine B, Hardwick JM, Griffin DE
TI - Persistence of alphaviruses in vertebrate hosts. [Review]
SO - Trends in Microbiology 1994 Jan;2(1):25-8
AB - Alphaviruses are a group of arthropod-borne, positive-strand RNA viruses that cause acute encephalitis or arthritis. These viruses were previously thought to cause only acute infections in vertebrates, but recent evidence suggests that host immunological and tissue-specific factors may act together to promote the persistence of alphavirus genomes in vivo. [References: 34]

AU - Vene S, Franzen C, Niklasson B
TI - Development of specific antibody patterns and clinical symptoms following Ockelbo virus infection.
SO - Arch. Virol. 1994;134(1-2):61-71
AB - Sixteen patients with symptoms typical for Ockelbo disease (rash, arthralgia, fever) were enrolled in a 2 1/2 year study, during which clinical symptoms were recorded and ELISA was employed to study specific IgM, IgG and IgG subclass development. Initially, all patients presented with rash and arthralgia, and five patients still suffered from joint symptoms at the end of the study period. Ockelbo virus specific IgM was detected during the first week post onset in 6 patients and in 15 patients by day 14. One patient failed to develop specific IgM and was later diagnosed with a human parvovirus B19 infection. All patients were IgM-negative 2 1/2 years post onset. Seroconversions or significant titer rises for specific total IgG were seen in 15 patients. IgG titers generally peaked within one year but in two patients maximum titers were seen 2 1/2 years post onset. Development of IgG1 followed that of total IgG, while IgG3, after an initial increase in all Ockelbo disease patients, remained at peak levels for one year in four patients, three of whom still had detectable IgG3 at the end of the study period. Ockelbo virus specific IgG2 or IgG4 was not detected in any of the patients.

AU - Olivo PD, Frolov I, Schlesinger S
TI - A cell line that expresses a reporter gene in response to infection by Sindbis virus: a prototype for detection of positive strand RNA viruses.
SO - Virology 1994 Jan;198(1):381-4
AB - We describe a stably transformed cell line (BHKSINLuc2) that contains a defective Sindbis virus genome under the control of a Rous sarcoma virus promoter and the luciferase gene downstream of the viral subgenomic RNA promoter. This cell line expresses high levels of luciferase activity following infection with Sindbis virus and provides a sensitive assay for titering variants of Sindbis virus that lack the structural protein genes, in particular, Sindbis virus replicons that express heterologous proteins. Cell lines such as this may be of value for detection of positive-strand RNA viruses.

AU - Roehrig JT
TI - Immunogens of encephalitis viruses.
SO - Veterinary Microbiology 1993 Nov;37(3-4):273-84
AB - The equine encephalitis viruses are members of the genus Alphavirus, in the family Togaviridae. Three main virus serogroups represented by western (WEE), eastern (EEE) and Venezuelan equine encephalitis (VEE) viruses cause epizootic and enzootic infection of horses throughout the western hemisphere. All equine encephalitis viruses are transmitted through the bite of an infected mosquito. The first equine encephalitis virus vaccines were produced by virus inactivation. Problems with inadequate inactivation, which may have caused a major epidemic/epizootic of VEE in central America and Texas in the 1970s, led to the development of a live attenuated VEE virus vaccine (TC-83) derived by cell culture passage. Inactivated vaccines are still used to prevent equine infections with WEE and EEE viruses. Alphaviruses are small single stranded, positive sense RNA viruses. The 12000 nucleotide genome is enclosed in an icosahedral nucleocapsid composed of multiple copies of the capsid (C) protein. The virion is enveloped. The membrane is modified by the insertion of heterodimers of two glycoproteins: E1 and E2. Monoclonal antibody analysis of the surface glycoproteins have provided a detailed understanding of important protective antigens. Recent studies comparing gene sequences from virulent and avirulent VEE viruses have begun to delineate mechanisms of alphavirus attenuation.

AU - Lundstrom JO, Vene S, Saluzzo JF, Niklasson B
TI - Antigenic comparison of Ockelbo virus isolates from Sweden and Russia with Sindbis virus isolates from Europe, Africa, and Australia: further evidence for variation among alphaviruses.
SO - Am. J. Trop. Med. Hyg. 1993 Nov;49(5):531-7
AB - The plaque-reduction neutralization test (PRNT) was used to compare 15 isolates of Ockelbo virus from Sweden, one isolate of Ockelbo virus from Russia, the Egyptian prototype Sindbis virus, and Sindbis-like viruses from Slovakia, South Africa, Cameroon, and Australia. Strains from northern Europe (Sweden and Russia) were indistinguishable by PRNT. We observed some antigenic variation between isolates of Sindbis virus from Europe, Africa, and Australia. An Australian strain (C-377) was shown to be distinct from prototype Sindbis virus, and the Acrocephalus strain from Slovakia was shown to be identical to prototype Sindbis virus. All other strains, including Ockelbo virus isolates, were shown to be subtypes of prototype Sindbis virus.

AU - Weaver SC, Hagenbaugh A, Bellew LA, Netesov SV, Volchkov VE, Chang GJ, Clarke DK, Gousset L, Scott TW, Trent DW, et al
TI - A comparison of the nucleotide sequences of eastern and western equine encephalomyelitis viruses with those of other alphaviruses and related RNA viruses [published erratum appears in Virology 1994 Aug 1;202(2):1083].
SO - Virology 1993 Nov;197(1):375-90
AB - The complete nucleotide sequence of a 1982 Florida strain of eastern equine encephalomyelitis (EEE) virus, and partial sequence of the nonstructural protein genes of western equine encephalomyelitis (WEE) virus, were determined. The EEE virus genome was 11,678 nucleotides in length, excluding the cap nucleotide and poly(A) tail, and the nucleotide composition was 28% A, 24% G, 25% C, and 23% U. The organization of both EEE and WEE virus genomes was like that of other alphaviruses and included a termination codon between the nsP3 and nsP4 genes. Codon usage for 10 of 20 amino acids was nonrandom in the EEE genome, and dinucleotide CpG-containing codons were underutilized in both genomes. The slight CpG deficiency was similar to that seen in other alphaviruses and plant viruses in the alphavirus-like group, but less than that of poliovirus and yellow fever virus. This slight deficiency may reflect adaptation for replication in both CpG-deficient vertebrates, as well as insects which do not have CpG-deficient genomes. Phylogenetic analyses using nonstructural protein amino acid sequences indicated that alphaviruses evolved from a common ancestor which existed a few thousand years ago. An intercontinental introduction of an ancestral virus from the Old to New World, or vice versa, probably resulted in two main extant groups: one includes New World (EEE and Venezuelan equine encephalitis) viruses, while the other includes Old World (Sindbis, Middelburg, O'nyong-nyong, Ross River, and Semliki Forest) viruses. The position of WEE virus in the phylogenetic trees indicated that, in addition to its capsid gene (C. S. Hahn et al. (1988) Proc. Natl. Acad. Sci. USA 85, 5997-6001), WEE virus acquired its nonstructural genes from an EEE-like ancestor during recombination.

AU - Anonymous
TI - From the Centers for Disease Control and Prevention. Arboviral diseases--United States, 1992.
SO - JAMA 1993 Jul 21;270(3):308

AU - Anonymous
TI - Arboviral diseases--United States, 1992.
SO - MMWR - Morbidity & Mortality Weekly Report 1993 Jun 25;42(24):467-8

AU - Wages DP, Ficken MD, Guy JS, Cummings TS, Jennings SR
TI - Egg-production drop in turkeys associated with alphaviruses: eastern equine encephalitis virus and Highlands J virus.
SO - Avian Diseases 1993 Oct-Dec;37(4):1163-6
AB - Alphaviruses were isolated from tracheas of turkey breeders in two North Carolina flocks experiencing a severe drop in egg production. Highlands J virus was isolated from one of the breeder flocks, in which production decreased by as much as 72.6% in selected houses over a 48-to-96-hour period. Eastern equine encephalitis virus was isolated from the second breeder flock, which experienced an egg-production drop of 44.5%. Clinical signs in both flocks were similar, with inactivity and the egg-production drop being the only clinical signs observed. Eggs from affected breeders were small and white, and a few were soft-shelled. Sera collected from the flocks 2 to 3 weeks after production began dropping confirmed the presence of antibodies to the viruses recovered. In the first flock, egg production failed to return to above 50%, although heat stress may have played a role in production recovery. The second flock was taken out of production and recycled.

AU - Lindsay MD, Broom AK, Wright AE, Johansen CA, Mackenzie JS
TI - Ross River virus isolations from mosquitoes in arid regions of Western Australia: implication of vertical transmission as a means of persistence of the virus.
SO - Am. J. Trop. Med. Hyg. 1993 Dec;49(6):686-96
AB - Outbreaks of mosquito-borne Ross River (RR) virus disease (epidemic polyarthritis) occur suddenly in the arid north and interior of the State of Western Australia, often within a few weeks of heavy rainfall. Between outbreaks, these regions may undergo long periods of drought, with little or no mosquito or arbovirus activity. The means by which RR virus is reintroduced or reactivated in these areas when environmental conditions favor mosquito-borne virus activity are unknown. In this paper, we describe isolations of RR virus from eight mosquito species trapped at two different locations, one coastal and one inland, in the arid Pilbara region of Western Australia, prior to outbreaks of epidemic polyarthritis. The isolation of RR virus has not been previously reported for five of these species and the isolations from the other three species are new records for Western Australia. The timing and number of isolations of RR virus from Aedes (Ochlerotatus) vigilax (Skuse, 1889) implicate that species as a vector of the virus on the Pilbara coast. Significantly, RR virus was isolated from pools of male Ae. vigilax and male Ae. (Macleaya) tremulus (Theobald, 1903) mosquitoes. This is the first report of RR virus (or other Australian arbovirus) isolates from wild-caught male mosquitoes. Both Ae. vigilax and Ae. tremulus have desiccation-resistant eggs that can survive long periods of drought, making them ideal candidates for the overwintering of arboviruses. The findings implicate vertical transmission as a means of persistence of RR virus in arid regions of Australia and therefore offer a likely explanation for the sudden recurrence of virus activity after heavy rains.

AU - Wolstenholme J
TI - Ross River virus disease--the first recorded outbreak?.
SO - Australian & New Zealand Journal of Medicine 1993 Aug;23(4):417-8

AU - Ficken MD, Wages DP, Guy JS, Quinn JA, Emory WH
TI - High mortality of domestic turkeys associated with Highlands J virus and eastern equine encephalitis virus infections.
SO - Avian Diseases 1993 Apr-Jun;37(2):585-90
AB - High mortality occurred in two flocks of commercial turkey hens placed in southern North Carolina in fall 1991. Daily mortality peaked at 3.19% in Flock 1 and 3.79% in Flock 2. Clinical signs included restlessness, somnolence, vocalization, and acute death. Gross lesions included atrophy of the bursa of Fabricius, thymus, and spleen, and watery intestinal contents. Microscopic changes included moderate to marked lymphocyte necrosis and depletion in the bursa, thymus, and spleen, widely scattered necrosis of pancreatic acinar cells, and mild villous atrophy and fusion in the jejunum and ileum with cuboidal to low columnar epithelial cells covering the villous tips. In Flock 1, at 27 days of age, reovirus and picornavirus particles were detected in the feces. One week later, togavirus-like particles were observed in fecal contents, and two of seven serum samples showed seroconversion to Highlands J virus. Eleven days later, five of six serum samples were positive for antibodies against Highlands J virus, with a fourfold increase in the geometric mean titer. In Flock 2, seroconversion to eastern equine encephalitis virus was observed in four of 10 serum samples 11 days after the onset of clinical signs. Based on the above observations, it is suspected that these alphaviruses were the cause of the clinical syndrome.

AU - Guy JS, Ficken MD, Barnes HJ, Wages DP, Smith LG
TI - Experimental infection of young turkeys with eastern equine encephalitis virus and highlands J virus.
SO - Avian Diseases 1993 Apr-Jun;37(2):389-95
AB - Depression, somnolence, and increased mortality were observed in 2-week-old turkeys inoculated intramuscularly with either eastern equine encephalitis (EEE) virus or Highlands J (HJ) virus. Mortality rates in EEE virus- and HJ virus-inoculated turkeys were 7/30 (23%) and 9/30 (27%), respectively; no sham-inoculated controls died. Both EEE virus- and HJ virus-inoculated turkeys developed viremia that lasted 2 days; peak mean titers were 5.5 and 3.2 log10 plaque-forming units per ml of blood, respectively. Pathologic changes in both EEE virus- and HJ virus-inoculated turkeys consisted primarily of multifocal necrosis in the heart, kidney, and pancreas, and lymphoid necrosis and depletion in the thymus, spleen, and bursa of Fabricius. The findings indicate that EEE virus and HJ virus are pathogenic for young turkeys.

AU - de Andrade AF, Carvalho M da G
TI - Metabolic and morphological changes in A. albopictus cells infected with Mayaro virus under heat-shock conditions.
SO - Arch. Virol. 1993;131(1-2):101-14
AB - We addressed the question how temperature elevation inhibits Mayaro virus replication in Aedes albopictus infected cells. The morphology and macromolecular changes induced by temperature, infection and high serum concentration were investigated in these cells. Cells incubated with 2 and 10% serum at 28 degrees C disclosed an intense vacuolization and inhibition of [35S]methionine incorporation in a time-dependent manner. 34 and 50 kDa viral structural proteins were detected 24 h after infection. In contrast, an inhibition of viral proteins synthesis occurred when infected cells were kept at 37 degrees C (heat-shock conditions). Total cellular RNA was isolated from mock and infected cells incubated at 28 or 37 degrees C. Northern blot analysis with a Mayaro genomic probe coding for viral structural proteins showed a decrease in the amount of viral 26S RNA in stressed cells when compared to those kept at 28 degrees C. Taken together, these results suggest that the inhibition of viral proteins synthesis in response to temperature elevation is associated with a decrease in the amount of subgenomic 26S RNA.

AU - Lundstrom JO, Turell MJ, Niklasson B
TI - Viremia in three orders of birds (Anseriformes, Galliformes and Passeriformes) inoculated with Ockelbo virus.
SO - Journal of Wildlife Diseases 1993 Apr;29(2):189-95
AB - One-hundred six birds of 14 species were inoculated with approximately 10(2.7) plaque-forming units of Ockelbo virus and bled daily for 5 days to determine viremia levels. Virus was detected in birds of all 14 species tested (four Anseriformes, one Galliformes and nine Passeriformes). The onset of viremia occurred earlier and viral titers were higher in very young anseriforms and galliforms than in older birds. Adult passeriforms had Ockelbo viremias of higher titer and longer duration than did adult anseriforms. Viremia titers in adult birds of all three orders tested were sufficient to induce high transmission rates in enzootic mosquito vectors, and viremias in passeriforms could induce high transmission rates in bridging vectors as well. Passeriforms of the genera Turdus and Fringilla could serve as amplification hosts for Ockelbo virus based on the presently demonstrated viremia of high titer and long duration in these birds, and the previously demonstrated high prevalence of Ockelbo virus neutralizing antibodies in free-ranging individuals and great population size compared to birds of other taxa. Bird species of all three orders tested, however, could function as incidental hosts of the virus.

AU - Hopla CE, Francy DB, Calisher CH, Lazuick JS
TI - Relationship of cliff swallows, ectoparasites, and an Alphavirus in west-central Oklahoma.
SO - J. Med. Entomol. 1993 Jan;30(1):267-72
AB - Approximately 250 isolates of a newly recognized virus, related to western equine encephalitis virus (family Togaviridae, genus Alphavirus), were obtained from cimicid bugs, Oeciacus vicarius; Cliff Swallows, Hirundo pyrrhonata; and House Sparrows, Passer domesticus in a study area in west-central Oklahoma at Buggy Creek and Caddo Canyons. Antigenicity of the virus strains varied slightly from isolate to isolate. This paper summarizes the ecology of the area by describing in general the flora and fauna there.

AU - Li XD, Qiu FX, Yang H, Rao YN, Calisher CH
TI - Isolation of Getah virus from mosquitos collected on Hainan Island, China, and results of a serosurvey.
SO - Southeast Asian Journal of Tropical Medicine & Public Health 1992 Dec;23(4):730-4
AB - An isolate of Getah virus was obtained from Culex mosquitos collected in Mao'an Village, Baoting County, Hainan Province, China, in 1964. The virus (strain M-1) replicated in laboratory-bred Aedes aegypti and Cx. fatigans (= quinquefasciatus), and was transmitted by laboratory-bred Ae. albopictus to healthy newborn albino mice. Skeletal muscles of newborn albino mice experimentally infected with the virus showed degeneration, atrophy, necrosis, and inflammatory changes of muscle fibers. Antibody prevalence in humans and animals ranged from 10.3% by neutralization tests of samples from healthy people in 1979 to 26.4% by CF tests of samples from people with febrile illnesses in 1982. The high prevalence of antibody in pigs, horses, and goats (17.6% to 37.5%) indicated that infection with Getah or a closely related virus is relatively common in domestic animals.

AU - Vinskaia AI, Proskriakova OF, Gorban' SG, Strelets IV, Kuznetsova GI
TI - [The identification of alphaviruses by using cDNA probes complementary to the 3'-terminal of the viral genome]. [RUSSIAN]
SO - Voprosy Virusologii 1992 Mar-Apr;37(2):113-6
AB - Venezuelan equine encephalomyelitis, Eastern equine encephalomyelitis and Sindbis viruses, as well as members of various serological groups of alphaviruses were identified using synthesized molecular probes complementary to 3'-terminus of the molecule of the appropriate genomic RNA: 32P-single-stranded kDNA and E. coli-cloned 32P-double-stranded kDNA. A high species-specificity of kDNA-probes was demonstrated. The sensitivity of the method was 1 ng of viral RNA overlayed on the nitrocellulose filter.

AU - Gu HX, Artsob H, Lin YZ, Wang DM, Zhao BY, Long QZ
TI - Arboviruses as aetiological agents of encephalitis in the People's Republic of China.
SO - Trans. R. Soc. Trop. Med. Hyg. 1992 Mar-Apr;86(2):198-201
AB - A serological study was undertaken to determine the role of arboviruses as etiological agents of encephalitis in the People's Republic of China (PRC). Paired sera were collected during mosquito seasons in 1988-1990 from 614 patients with possible viral encephalitis in 15 regions of PRC and tested for haemagglutination inhibiting antibodies to selected arboviruses. Seroconversions were documented to alphavirus and flavivirus antigens in 13.0 and 18.7% of patients respectively in most of the study areas. No California group seroconversion was detected. The age of alphavirus seroconvertors ranged from 2 months to 32 years and of flavivirus seroconvertors from 6 months to 50 years, with higher numbers in males. Serious central nervous system manifestations were seen more commonly in flavivirus seroconvertors. This study affirms the importance of flavivirus as causative agents of encephalitis in PRC and provides evidence that one or more alphaviruses are causing symptomatic infections with neurological involvement in PRC.

AU - Weaver SC, Rico-Hesse R, Scott TW
TI - Genetic diversity and slow rates of evolution in New World alphaviruses. [Review]
SO - Curr. Top. Microbiol. Immunol. 1992;176:99-117

AU - Turell MJ, Beaman JR, Tammariello RF
TI - Susceptibility of selected strains of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) to chikungunya virus.
SO - J. Med. Entomol. 1992 Jan;29(1):49-53
AB - The relative susceptibility of selected strains of Aedes aegypti (L.) and Aedes albopictus (Skuse) fed on a viremic monkey to infection with chikungunya virus was determined. Infection rates were consistently higher in 10 strains of Ae. albopictus tested than in 7 strains of Ae. aegypti tested, regardless of the geographic location from which the strains originated or the dose of virus ingested. Similarly, virus dissemination rates were higher in the Ae. albopictus strains compared with the Ae. aegypti strains. For nearly all (11 of 12) strains tested of both species, groups of mosquitoes with one or more females with a disseminated infection transmitted virus by bite to weanling mice. Based on these studies, Ae. albopictus appears to be a more competent laboratory vector of chikungunya virus than does Ae. aegypti.

AU - Lundstrom JO, Turell MJ, Niklasson B
TI - Antibodies to Ockelbo virus in three orders of birds (Anseriformes, Galliformes and Passeriformes) in Sweden.
SO - Journal of Wildlife Diseases 1992 Jan;28(1):144-7
AB - Sera from 324 birds collected in an Ockelbo virus disease endemic area in central Sweden were examined for the presence of specific antibodies to Ockelbo virus by a plaque reduction neutralization test. Birds examined belonged to the orders Anseriformes (n = 207), Galliformes (n = 66) and Passeriformes (n = 51). Ockelbo virus neutralizing antibodies were detected in 26 (8%) of the specimens, including species from each of the three orders tested. Specific antibodies found in caged birds and in 6- to 10-week-old birds suggested local transmission. The highest antibody prevalence (27%, 14/51) was observed in the Passeriformes in which 5 of 9 species tested contained antibodies. The high antibody prevalence in passeriforms and the very large population of this group in relation to other avian groups in Sweden gives them a high potential as amplification hosts for Ockelbo virus.

AU - da Costa Carvalho MG, Fournier MV
TI - Effect of heat shock on gene expression of Aedes albopictus cells infected with Mayaro virus.
SO - Research in Virology 1991 Jan-Feb;142(1):25-31
AB - Three major Mayaro virus proteins of 62, 50 and 34 kDa were detected in Aedes albopictus cells after 48 h postinfection at 28 degrees C. When the infected cells were shifted from 28 to 37 degrees C for 90 min (heat shock conditions), the synthesis of two major heat shock proteins (HSP) 82 and 70 kDa was induced concomitantly with strong inhibition of virus and normal protein synthesis. Total cellular RNA was isolated from mock and infected cells incubated at 28 degrees C or under heat shock. Northern blot analysis with HSP genomic probes from Drosophila sp showed that (1) the probe for HSP 82 hybridized with an RNA of 2.6 kb present only in heat-shocked cells, (2) the HSP 70 probe hybridized with RNA species of 2.5 kb, present only in RNA from heat-shocked cells. These results showed that Mayaro virus was not able to alter the reprogrammation of gene expression induced by heat shock in A. albopictus cells.

AU - Anonymous
TI - Barmah Forest virus [editorial].
SO - Lancet 1991 Apr 20;337(8747):948-9

AU - Vasconcelos MC, Frugulhetti IC, Rebello MA
TI - Effect of hypertonic medium on the protein synthesis in L-A9 and Aedes albopictus cells infected with Mayaro virus.
SO - Memorias do Instituto Oswaldo Cruz 1991 Jul-Sep;86(3):365-6

AU - Asai T, Shibata I, Uruno K
TI - Susceptibility of pregnant hamster, guinea pig, and rabbit to the transplacental infection of Getah virus.
SO - Journal of Veterinary Medical Science 1991 Dec;53(6):1109-11

AU - Kamada M, Kumanomido T, Wada R, Fukunaga Y, Imagawa H, Sugiura T
TI - Intranasal infection of Getah virus in experimental horses.
SO - Journal of Veterinary Medical Science 1991 Oct;53(5):855-8
AB - Aerosol transmission in equine Getah virus (GV) infection was examined by intranasal inoculation with 10(3.0) to 10(7.0) TCID50 of the MI-110 strain in 7 experimental horses. The establishment of intranasal infection of GV was confirmed in all these horses by detecting serum neutralizing antibody against the MI-110 strain. Horses inoculated with more than 10(4.0) TCID50 of the virus manifested mild pyrexia, eruptions, serous nasal discharge, lymphopenia or monocytosis. Viremia ranging from 10(1.0) to 10(3.5) TCID50/0.2 ml occurred in horses inoculated with 10(5.0) TCID50, or more. Virus recovery from the nasal cavity was observed only in horses inoculated with 10(7.0) TCID50, and the viral titers recorded were 10(3.0) TICD50/ml or less. From these results, it is assumed that GV disseminated from the nasal cavity of naturally infected horses, except for intranasal infection with a lot of the virus, is probably very low in titer. So it seems to be rare that GV in natural cycles is spread from horse to horse by aerosol transmission.

AU - Kamada M, Wada R, Kumanomido T, Imagawa H, Sugiura T, Fukunaga Y
TI - Effect of viral inoculum size on appearance of clinical signs in equine Getah virus infection.
SO - Journal of Veterinary Medical Science 1991 Oct;53(5):803-6
AB - A study was performed to examine the effect of viral inoculum size on the appearance of clinical signs in equine Getah virus (GV) infection by intramuscular inoculation with 10(1.3) to 10(6.3) TCID50 of the MI-110 strain in 6 experimental horses. When inoculated with more than 10(3.3) TCID50 of the virus, every horse developed pyrexia, edema in the hind legs, serous nasal discharge, lymphopenia and viremia in the relatively early stage of disease. On the other hand, enlargement of the submandibular lymph node was observed only in horses inoculated with 10(5.3) and 10(6.3) TCID50 of the virus, while typical eruptions were developed in every horse inoculated with 10(4.3) TCID50 or less. These results demonstrated that the appearance of clinical signs in equine GV infection was dependent on viral inoculum size. Besides, it was assumed to be rare chance that eruptions and enlargement of the submandibular lymph node were developed simultaneously in a horse.

AU - Shibata I, Hatano Y, Nishimura M, Suzuki G, Inaba Y
TI - Isolation of Getah virus from dead fetuses extracted from a naturally infected sow in Japan.
SO - Veterinary Microbiology 1991 May;27(3-4):385-91
AB - Three viruses producing a cytopathic effect in cell culture were isolated from dead fetuses extracted from a naturally infected sow, and were found to be serologically identical by neutralization tests. One of the viruses was cloned and named the Sakura strain. The Sakura strain was identified as Getah virus by cross-neutralization tests.

AU - Tarnvik A
TI - [The Ockelbo disease, nephropathia epidemica and tularemia. A great deal is known about the infectious diseases in the north--but quite a few question-marks are left]. [Review] [Swedish]
SO - Lakartidningen 1991 Jul 24;88(30-31):2515-8

AU - Smith GC, Francy DB
TI - Laboratory studies of a Brazilian strain of Aedes albopictus as a potential vector of Mayaro and Oropouche viruses.
SO - Journal of the American Mosquito Control Association 1991 Mar;7(1):89-93
AB - The vector efficiency of colonized Aedes albopictus from Brazil was assessed for Mayaro (MAY) and Oropouche (ORO) viruses. Female mosquitoes, 3-4 days old, were fed on a MAY-infected hamster with a viremia level of 5.3 log10 Vero cell plaque-forming units (PFU) of virus/ml or an ORO-infected hamster circulating 7.3 log10 PFU/ml. Mayaro infection rates among fed mosquitoes were 16.9 and 11% at 6, 13 and 20 days postfeeding, respectively, and 1/2 and 2/2 infected mosquitoes transmitted virus on days 13 and 20, respectively. Only 13, 5 and 3% of mosquitoes were infected with ORO virus at 6, 13 and 20 days, respectively, and no transmission occurred. Mosquitoes were also fed on 3 dilutions of MAY virus-blood suspensions in membrane feeders. The infection rate among mosquitoes fed the highest concentration (7.7 log10 PFU/ml) was 11/13 (85%), and 5/11 (46%) infected mosquitoes transmitted virus.

AU - Greiser-Wilke IM, Moennig V, Kaaden OR, Shope RE
TI - Detection of alphaviruses in a genus-specific antigen capture enzyme immunoassay using monoclonal antibodies.
SO - Journal of Clinical Microbiology 1991 Jan;29(1):131-7
AB - A genus-specific antigen capture assay using similar combinations of monoclonal antibodies for capture and detection of 24 alphaviruses belonging to the seven serocomplexes was developed. The sensitivity of the test ranged from 10(3.4) 50% tissue culture infective doses/ml for o'nyong-nyong virus to 10(6.1) 50% tissue culture infective doses/ml for Middelburg virus. The antigen capture test uses a combination of cross-reacting monoclonal antibodies directed against the nucleocapsid protein and envelope glycoprotein E1 of Semliki Forest virus.

AU - Koblet H
TI - The "merry-go-round": alphaviruses between vertebrate and invertebrate cells. [Review]
SO - Advances in Virus Research 1990;38:343-402

AU - Haas L, Moennig V, Kaaden OR
TI - Use of biotechnical methods in veterinary medicine.
SO - Revue Scientifique et Technique 1990 Mar;9(1):245-51
AB - Biotechnological methods offer promising approaches for improved diagnostic and prophylactic purposes. The following biotechnological techniques are used in the Institute of Virology at the Hanover Veterinary School:--Production of monoclonal antibodies directed against viral and bacteria-specific antigens such as bovine virus diarrhoea virus, classical swine fever (hog cholera) virus, feline leukaemia virus, animal parvoviruses, Alphavirus, Brucella and Francisella--Establishment of improved and sensitive diagnostic enzyme immunoassays (ELISA) using monoclonal antibodies--Molecular cloning and sequencing of classical swine fever virus RNA and parvovirus DNA--Development of diagnostic hybridisation techniques (dot, slot, Southern and Northern blot, in situ, oligonucleotides)--Detection of viral genomes in tissues of infected animals--Development of synthetic oligopeptides as diagnostic antigens and as potential immunogens for vaccines. Currently available techniques used in basic research (e.g. pathogenesis studies) will be tested for their application in routine diagnosis of viral diseases, e.g. by molecular hybridisation. Some techniques need to be simplified (e.g. RNA extraction procedures) and, particularly, alternative labelling schedules must be developed (e.g. biotin or sulfone labelling instead of radionuclides).

AU - Sowden D, McCormack JG
TI - Barmah Forest virus [letter].
SO - Australian & New Zealand Journal of Medicine 1990 Oct;20(5):750

AU - Uryvaev LV, Zlobin AIu, Berezina LK, Ionova KS, Glushchenko OP, Parasiuk NA, Skvortsova TM, L'vov DK
TI - [A comparative analysis of the polypeptides of the the Sindbis and Karelian fever viruses]. [RUSSIAN]
SO - Voprosy Virusologii 1990 Sep-Oct;35(5):393-6
AB - In pulse-chase experiments with Karelian fever virus-infected cells, proteins were found with molecular weights of 130, 98, 78, and 62 kD of which the first, second and fourth were classified as polypeptide precursors of the structural proteins of virion. The molecular weights of proteins E1, E2 and C of 52, 47 and 34 kD, respectively, as well as isoelectric points of isolated glycoproteins (pI E1 = 6.3, pI E2 = 8.4) were similar in KFV (strain Leiv-9298) and Sindbis virus (strain AR339). The antigenic similarity of the strains under study in neutralization test with hyperimmune sera, the identity of physicochemical characteristics of the structural proteins of KFV and prototype Sindbis virus strain suggest a close relationship of the Leiv-9298 strain to the Afro-European variants of Sindbis virus.

AU - Turell MJ, Lundstrom JO
TI - Effect of environmental temperature on the vector competence of Aedes aegypti and Ae. taeniorhynchus for Ockelbo virus.
SO - Am. J. Trop. Med. Hyg. 1990 Nov;43(5):543-50
AB - Studies were conducted to determine the effect of environmental temperature on the ability of Aedes aegypti and Ae. taeniorhynchus to transmit Ockelbo (OCK) virus. Temperatures tested were 10 degrees C, 17 degrees C, 24 degrees C, and a cyclic (10-24 degrees C, mean = 17 degrees C) regimen designed to mimic continuously temperatures to which a mosquito might be exposed in July and August in central Sweden. Both species were highly susceptible to oral infection, with no consistent association between incubation temperature and infection rates. However, dissemination of OCK virus to the hemocoel in infected mosquitoes was directly related both to the dose of virus ingested and to the extrinsic incubation temperature. After greater than or equal to 14 days extrinsic incubation, once a disseminated infection was achieved, transmission by bite to a susceptible chick did not appear to be affected by either the initial dose ingested, the holding temperatures of 17 degrees C, 24 degrees C, nor the cyclic regimen. When re-fed, 93% (68/73) and 82% (67/82) of the disseminated Ae. taeniorhynchus and Ae. aegypti, respectively, transmitted virus. In contrast, when mosquitoes were held at 10 degrees C, fewer disseminated Ae. taeniorhynchus (0/5) and Ae. aegypti (2/6) transmitted virus. There were no significant differences in infection, dissemination, or transmission rates for Ae. taeniorhynchus held at the cyclic temperature regimen vs. those held at a constant 17 degrees C. Environmental temperature affected the vectorial capacity of Ae. aegypti and Ae. taeniorhynchus for OCK virus, with transmission occurring earlier and at a higher rate in mosquitoes held at higher temperatures.

AU - Lundstrom JO, Turell MJ, Niklasson B
TI - Effect of environmental temperature on the vector competence of Culex pipiens and Cx. torrentium for Ockelbo virus.
SO - Am. J. Trop. Med. Hyg. 1990 Nov;43(5):534-42
AB - The effects of environmental temperature on Ockelbo virus infection, dissemination, and transmission were studied in Culex torrentium and in the Uppsala and the El Gabal strains of Cx. pipiens. Temperatures tested included 10 degrees C, 17 degrees C, 24 degrees C, and a cyclic (10-24 degrees C, mean = 17 degrees C) regimen designed to mimic typical hourly temperatures in an area endemic for Ockelbo disease in Sweden during the transmission season. The vector competence of both the Uppsala and the El Gabal strains of Cx. pipiens was directly related to environmental temperature. Mosquitoes held at 10 degrees C had a reduced ability to transmit virus as compared to those held at 17 degrees C, 24 degrees C, or in the cyclic temperature regimen. A rapid increase in dissemination rates was observed in mosquitoes exposed to a shift in temperature from 10 degrees C to 24 degrees C. After 4 days at 24 degrees C, these mosquitoes had vector competence similar to those held at 24 degrees C for the entire incubation time. In contrast, virus dissemination in Cx. torrentium was rapid at all temperatures tested and appeared unaffected by environmental temperature; infection and dissemination rates were consistently higher in Cx. torrentium than in either the Uppsala or the El Gabal strains of Cx. pipiens. It seems the transmission of Ockelbo virus by Cx. pipiens might be interrupted by a prolonged period of cold weather, while transmission by Cx. torrentium would continue.

AU - Aldred J, Campbell J, Davis G, Lehmann N, Wolstenholme J
TI - Barmah Forest virus in the Gippsland Lakes region, Victoria [letter].
SO - Medical Journal of Australia 1990 Oct 1;153(7):434

AU - Hohdatsu T, Ide S, Yamagishi H, Eiguchi Y, Nagano H, Maehara N, Tanaka Y, Fujisaki Y, Yago K, Taguchi K, et al
TI - Enzyme-linked immunosorbent assay for the serological survey of Getah virus in pigs.
SO - Nippon Juigaku Zasshi - Japanese Journal of Veterinary Science 1990 Aug;52(4):835-7

AU - Lundstrom JO, Niklasson B, Francy DB
TI - Swedish Culex torrentium and Cx. pipiens (Diptera: Culicidae) as experimental vectors of Ockelbo virus.
SO - J. Med. Entomol. 1990 Jul;27(4):561-3
AB - The ability of the sibling species Culex pipiens (L.) and Culex torrentium (Martini) from central Sweden to transmit Ockelbo (OCK) virus was determined. Both species became infected after ingesting OCK virus from a viremic chicken; they transmitted this virus to chickens after 21-28 d of extrinsic incubation. In Cx. torrentium, infection rates were 90% or higher, and all 10 refeeding mosquitoes transmitted virus after feeding on chickens with a viremia of at least 10(3.0) plaque-forming units (PFU)/ml. In contrast, only 1 of 28 (4%) of the Cx. pipiens that ingested blood containing 10(3.0-3.9) PFU/ml became infected, and none of 16 refeeding mosquitoes transmitted virus. However, 98 of 184 (53%) of the Cx. pipiens that ingested a blood meal containing at least 10(6.0) PFU/ml became infected. Transmission rates in Cx. pipiens increased with increasing virus concentration in the blood meal to a maximum of 37% in mosquitoes that ingested greater than 10(8.0) PFU/ml. Based on these data, both Cx. pipiens and Cx. torrentium are capable of transmitting OCK virus in an enzootic cycle involving birds as hosts. However, Cx. torrentium appears to be physiologically a more efficient vector than Cx. pipiens.

AU - Hohdatsu T, Takahasi N, Ide S, Yamagishi H, Saito H, Fujisaki Y, Koyama H
TI - The relation between pathogenicity and plaque size of Getah virus Kanagawa strain in suckling mice.
SO - Nippon Juigaku Zasshi - Japanese Journal of Veterinary Science 1990 Jun;52(3):519-26
AB - The relation among biological properties, particularly pathogenicity for suckling mice, and plaque size was studied in four virus strains: Getah virus strain Kanagawa; two strains obtained by plaque cloning of the Kanagawa strain, Getah Kanagawa SP (G-K-SP) strain which forms small plaques (SP) only and strain G-K-LP which forms large plaques (LP) only; and strain Haruna which forms SP only. There were no marked differences among the four strains in serological properties, growth curves and sensitivity to pH, trypsin and temperature. Strain G-K-LP showed higher pathogenicity for suckling mice than strain G-K-SP. However, the pathogenicity of strain Haruna, which forms SP only, was as high as that of strain G-K-LP. Some of the clones in SP of strain Kanagawa kill all mice in 5 to 6 days after inoculation while the others required 9 to 11 days or longer before causing death. The present study showed that the pathogenicity of Getah viruses shortly after being isolated from the field, such as the Kanagawa strain, is different between large and small plaques, and even among small plaques, at least in suckling mice, and that the pathogenicity has no relation to plaque size.

AU - Phillips DA, Murray JR, Aaskov JG, Wiemers MA
TI - Clinical and subclinical Barmah Forest virus infection in Queensland.
SO - Medical Journal of Australia 1990 May 7;152(9):463-6
AB - Barmah Forest virus is a mosquito-borne agent (alphavirus) reported to cause both clinical and subclinical infections in New South Wales. This report describes 29 cases of clinical Barmah Forest virus infection diagnosed between July 1988 and March 1989 (21 from Queensland, six from New South Wales and two from Victoria) and provides evidence of extensive subclinical infection with this virus (0.23% of the population per annum) throughout Queensland. It also includes a description of the first isolation of Barmah Forest virus from a patient. Data obtained in the course of the study suggest that Barmah Forest virus infections may not be diagnosed correctly in many instances because of the similarity of the symptoms of this disease to those of epidemic polyarthritis and the small number of laboratories providing the necessary serological services.

AU - Scott TW, Lorenz LH, Weaver SC
TI - Susceptibility of Aedes albopictus to infection with eastern equine encephalomyelitis virus.
SO - Journal of the American Mosquito Control Association 1990 Jun;6(2):274-8
AB - We examined susceptibility of a strain of Aedes albopictus from Houston, Texas to experimental infection with eastern equine encephalomyelitis (EEE) virus. After 15 days of extrinsic incubation, all Ae. albopictus examined by the cell culture assay and fluorescent antibody staining were infected but only 57% (4/7) of the mosquitoes that refed transmitted virus by bite. Data supported the concept of a salivary gland infection barrier to EEE virus in Ae. albopictus and the conclusion that virus replicates in fat body following dissemination from the midgut and prior to infection of salivary glands. Assay of adult progeny from females that fed on viremic chicks and fluorescent antibody studies of infected females failed to provide evidence that EEE virus is transmitted vertically by Ae. albopictus.

AU - Lahesmaa-Rantala R, Stahlberg TH, Granfors K, Kuusisto P, Toivanen A
TI - Serological cross-reactions against Yersinia enterocolitica in patients infected with other arthritis-associated microbes.
SO - Clinical & Experimental Rheumatology 1990 Jan-Feb;8(1):5-9
AB - In order to investigate arthritis-triggering, serologically cross-reactive antigens, sera from patients infected with arthritis-associated microbes, Salmonellae, Chlamydia trachomatis, and Sindbis-like alphavirus, were reacted against SDS-PAGE separated and immunoblotted Yersinia enterocolitica 0:3 antigens. These sera reacted with Yersinia to the same extent as did the control sera taken from patients with streptococcal, staphylococcal and Bordetella pertussis infections or from healthy blood donors. Moreover, the various sera produced different reactivity patterns, directed against several different antigens. Although sera from test subjects, as well as from controls including healthy individuals, recognized some Yersinia antigens, these patterns differed markedly from those recognized by sera taken from patients with Yersinia infection. Significantly, analysis of the reactivities against the different molecular weight antigen components of Yersinia revealed no dominant band or pattern which could thus have been defined as arthritis-associated.

AU - Turell MJ, Lundstrom JO, Niklasson B
TI - Transmission of Ockelbo virus by Aedes cinereus, Ae. communis, and Ae. excrucians (Diptera: Culicidae) collected in an enzootic area in central Sweden.
SO - J. Med. Entomol. 1990 May;27(3):266-8
AB - Studies were conducted to determine the ability of Aedes excrucians (Walker), Ae. cinereus Meigen, and Ae. communis (De Geer) group mosquitoes, collected in an Ockelbo (OCK) virus enzootic area in central Sweden, to transmit this virus. All three species were highly susceptible to infection; at least 96% of the specimens of each species became infected after ingesting blood from a viremic chicken. Recovery of virus from the legs of all 61 of the Ae. excrucians and from 51% (24 of 47) and 75% (6 of 8) of the Ae. cinereus and Ae. communis tested, respectively, indicated that OCK virus readily disseminated from the midgut to the hemocoel in these species. Although none of the Ae. communis refed, Ae. cinereus and Ae. excrucians successfully transmitted OCK virus by bite. Because these Aedes species are attracted to avian and mammalian hosts and because OCK virus has been isolated from field-collected specimens in Sweden and the USSR, Aedes mosquitoes should be considered a possible link between human infections and the enzootic cycle involving birds and Culex and Culiseta mosquitoes.

AU - Roehrig JT, Hunt AR, Chang GJ, Sheik B, Bolin RA, Tsai TF, Trent DW
TI - Identification of monoclonal antibodies capable of differentiating antigenic varieties of eastern equine encephalitis viruses.
SO - Am. J. Trop. Med. Hyg. 1990 Apr;42(4):394-8
AB - We have isolated and characterized 3 monoclonal antibody (Mab) reagents useful in the serological identification of varieties of eastern equine encephalitis (EEE) viruses. These antibodies were specific for the E1 glycoprotein of their homologous viruses. One Mab, 1B5C-3, reacted specifically with all North American (NA) EEE viruses isolated over a 50 year period. This antigenic stability of NA isolates was genetically confirmed by oligonucleotide fingerprinting. Evolutionary stability is a unique feature among alphaviruses. The Mab, 1C1J-4 reacted specifically with 1 South American isolate of EEE virus. A third Mab, 1B1C-4, was EEE virus complex reactive. While none of these antibodies had virus neutralizing activity, the identified reactivities could be demonstrated in the more rapid serological tests of enzyme-linked immunosorbent assay and indirect immunofluorescence.

AU - Calisher CH, Karabatsos N, Foster JP, Pallansch M, Roehrig JT
TI - Identification of an antigenic subtype of eastern equine encephalitis virus isolated from a human.
SO - Journal of Clinical Microbiology 1990 Feb;28(2):373-4
AB - Eastern equine encephalitis (EEE) virus was isolated from the cerebrospinal fluid of a 6-year-old male who had clinically diagnosed aseptic meningitis and subsequently died. Several standard serologic tests that use polyclonal antibody and indirect immunofluorescence and hemagglutination inhibition tests that use monoclonal antibody provided evidence that the isolate was an antigenic subtype of prototype North American EEE virus. We believe that this is the first evidence of an antigenic subtype of EEE virus.

AU - Levinson RS, Strauss JH, Strauss EG
TI - Complete sequence of the genomic RNA of O'nyong-nyong virus and its use in the construction of alphavirus phylogenetic trees.
SO - Virology 1990 Mar;175(1):110-23
AB - The alphaviruses are a group of about 25 positive-strand RNA viruses that are important human and veterinary pathogens and that are geographically dispersed. We report here the complete nucleotide sequence of the genomic RNA of the alphavirus, O'nyong-nyong virus. The RNA is 11,835 nucleotides in length and the organization of the genome is typical of alphaviruses. Phylogenetic trees were constructed from the protein sequences of O'nyong-nyong and six other alphaviruses. Trees were constructed for each nonstructural and structural viral protein individually in order to detect any possible recombination events, as well as to examine the differential divergence among the various proteins. The members of each tree can be divided into three subgroups: the Semliki Forest virus subgroup (Semliki Forest, O'nyong-nyong, and Ross River viruses), the eastern equine encephalitis virus subgroup (eastern equine encephalitis and Venezuelan equine encephalitis viruses), and the Sindbis virus subgroup. Sindbis virus, which is geographically restricted to the Old World, is more closely related to the eastern equine encephalitis subgroup, which are New World viruses, than it is to the Semliki Forest virus subgroup, which are mostly Old World viruses. Western equine encephalitis virus is a special case because it is a recombinant virus. Its nonstructural and capsid proteins are most closely related to those of eastern equine encephalitis virus while its glycoproteins are most closely related to those of Sindbis virus. All members of a given subgroup have diverged the same amount from their common node point. However, the structural proteins of the Semliki Forest virus subgroup are more closely related to one another than those of the eastern equine encephalitis virus subgroup. This difference probably indicates that the members of the eastern equine encephalitis virus subgroup diverged earlier than the members of the Semliki Forest virus subgroup, which suggests that the alphaviruses originated in the New World.

AU - Greiser-Wilke I, Moenning V, Kaaden OR, Figueiredo LT
TI - Most alphaviruses share a conserved epitopic region on their nucleocapsid protein.
SO - J. Gen. Virol. 1989 Mar;70 ( Pt 3):743-8
AB - Fourteen hybridoma cell lines secreting antibodies against the Semliki Forest virus nucleocapsid protein were established and employed for identification of conserved epitopes among 27 alphavirus types and subtypes. Using an antibody capture test, the antibodies were found to cross-react to variable degree with alphaviruses belonging to the Semliki Forest, western encephalitis and eastern encephalitis complexes, as well as Middelburg and Ndumu. None of the antibodies reacted with either Venezuelan equine encephalitis or Barmah Forest virus. Due to their reactivity with Fort Morgan, Y62-33, Whataroa and chikungunya, the monoclonal antibodies were divided into six reactive types. Competition assays showed that the epitopes for all the types were either identical or clustered on a single domain of the nucleocapsid protein.

AU - Scott TW, Weaver SC
TI - Eastern equine encephalomyelitis virus: epidemiology and evolution of mosquito transmission. [Review]
SO - Advances in Virus Research 1989;37:277-328

AU - Hubbard JL, Scott TW, Lorenz LH, Watts DM, Patrican LA
TI - Effects of triturated Culiseta melanura (Diptera: Culicidae) on recovery of eastern equine encephalomyelitis virus.
SO - J. Med. Entomol. 1989 Jul;26(4):380-3
AB - Experiments were done to determine the effect, if any, of larval and adult Culiseta melanura (Coquillett) suspensions on the recovery of eastern equine encephalomyelitis (EEE) virus in baby hamster kidney (BHK) and Vero cell cultures. Although triturated pools of this mosquito reduced the titer of EEE virus added to suspensions, suspensions prepared from as many as 100 Cs. melanura larvae or adults did not reduce titers of virus to undetectable levels. Similarly, the titer of EEE virus in orally infected female Cs. melanura remained detectable when a single infected mosquito was triturated in a pool with 99 uninfected mosquitoes. These results show that in BHK or Vero cell culture assay systems, triturated Cs. melanura do not completely prevent the detection of EEE virus. The results therefore indicate that mosquito suspensions would not interfere with the isolation of virus from field-collected mosquitoes. This conclusion suggests that mosquito suspensions were not a factor in previous studies that were unsuccessful at detecting transovarial transmission of EEE virus by Cs. melanura.

AU - Figueiredo LT, Nogueira RM, Cavalcanti SM, Schatzmayr H, da Rosa AT
TI - Study of two different enzyme immunoassays for the detection of Mayaro virus antibodies.
SO - Memorias do Instituto Oswaldo Cruz 1989 Jul-Sep;84(3):303-7
AB - This paper presents the evaluation of an enzyme immunoassay in which Mayaro virus-infected cultured cells are used as antigen (EIA-ICC) and an IgM antibody capture ELISA (MAC-ELISA) for Mayaro serologic diagnosis using 114 human sera obtained during a Mayaro outbreak occurred in Bolivia, in 1987. Results were compared with those obtained by haemagglutination-inhibition test (HAI). MAC-ELISA was the most sensitive technique for anti-Mayaro IgM detection. MAC-ELISA was twice as sensitive as IgM EIA-ICC. The data shows that MAC-ELISA is a practical and valid technique for diagnosis of recent Mayaro infection. IgG EIA-ICC showed high sensitivity and high specificity compared to HAI. The combination of anti-Mayaro IgG and IgM EIA-ICC results presented the highest sensitivity of the study. Anti-Mayaro IgG and IgM simultaneous detection by EIA-ICC can be used for recent infection diagnosis (in spite of a less sensitive IgM detection than by MAC-ELISA), for surveillance and sero-epidemiologic studies, and for studies of IgG and IgM responses to Mayaro infection.

AU - Juricova Z, Hubalek Z, Halouzka J, Hudec K, Pellantova J
TI - Results of arbovirological examination of birds of the family Hirundinidae in Czechoslovakia.
SO - Folia Parasitologica 1989;36(4):379-83
AB - Migratory birds (swallow, Hirundo rustica; sand martin, Riparia riparia; house martin, Delichon urbica) caught in southern Moravia (Czechoslovakia) in 1984-87 were examined for arbovirus infections. Isolation experiments were carried out using blood samples of 183 birds (52 swallows, 107 sand martins, and 24 house martins). The results were negative. Serological examinations of 136 birds (36 swallows, 86 sand martins, and 14 house martins) were made by haemagglutination-inhibition test (HIT) using 6 arboviral antigens of the genera Alphavirus (Sindbis--SIN) and Flavivirus (tick-borne encephalitis--TBE, West Nile--WN) and of the family Bunyaviridae (Tahyna--TAH, Calovo, CVO, and Bhanja--BHA). Antibodies against all of the tested viruses were detected at different rates: SIN 2.9%, TBE 1.5%, WN 1.5%, TAH 4.4%, CVO 1.5%, and BHA 2.2%. The titres ranged from 1.20 to 1.80.

AU - Vazquez Ramudo S, Guzman Tirado MG, Monteagudo Borges R
TI - [Serologic study of arbovirus in 2 localities of the Juventud island]. [Spanish]
SO - Revista Cubana de Medicina Tropical 1989 Sep-Dec;41(3):362-70
AB - A serologic study is made in two population groups in the Isle of Youth. A total 268 blood samples in blotting paper are subjected to the hemagglutination inhibition technique, using the Eastern equine encephalomyelitis, Western equine encephalomyelitis, Saint Louis encephalitis, and dengue 2 viruses; 16% positivity to flavivirus was found. A second serum sample was taken in people positive by the hemagglutination inhibition technique in order to carry out the techniques of complement fixation and plate reduction neutralization. Nine cases showed complement-fixating antibodies, which is indicative of recent infection and in 29 cases neutralizing antibodies to SLE virus were found.

AU - Rodhain F, Gonzalez JP, Mercier E, Helynck B, Larouze B, Hannoun C
TI - Arbovirus infections and viral haemorrhagic fevers in Uganda: a serological survey in Karamoja district, 1984.
SO - Trans. R. Soc. Trop. Med. Hyg. 1989 Nov-Dec;83(6):851-4
AB - Sera collected in May 1984 from 132 adult residents of Karamoja district, Uganda, were examined by haemagglutination inhibition tests for antibodies against selected arboviruses, namely Chikungunya and Semliki Forest alphaviruses (Togaviridae); dengue type 2, Wesselsbron, West Nile, yellow fever and Zika flaviviruses (Flaviviridae); Bunyamwera, Ilesha and Tahyna bunyaviruses (Bunyaviridae); and Sicilian sandfly fever phlebovirus (Bunyaviridae); and by immunofluorescence tests against certain haemorrhagic fever viruses, Lassa fever arenavirus (Arenaviridae), Ebola-Sudan, Ebola-Zaire and Marburg filoviruses (Filoviridae), Crimean-Congo haemorrhagic fever nairovirus and Rift Valley fever phlebovirus (Bunyaviridae). Antibodies against Chikungunya virus were the most prevalent (47%), followed by flavivirus antibodies (16%), which were probably due mainly to West Nile virus. No evidence of yellow fever or dengue virus circulation was observed. A few individuals had antibodies against Crimean-Congo haemorrhagic fever, Lassa, Ebola and Marburg viruses, suggesting that these viruses all circulate in the area.

AU - Walton TE, Jochim MM, Barber TL, Thompson LH
TI - Cross-protective immunity between equine encephalomyelitis viruses in equids.
SO - American Journal of Veterinary Research 1989 Sep;50(9):1442-6
AB - Eighteen equids were inoculated with eastern equine encephalomyelitis (EEE) and 18 equids with western equine encephalomyelitis (WEE) viruses to produce EEE virus- and WEE virus-immunized equids. Twelve surviving EEE virus-seropositive equids, 15 surviving WEE virus-seropositive equids, and 10 nonimmunized, seronegative equids (controls) were subsequently inoculated with an equine pathogenic (epizootic) strain of Venezuelan equine encephalomyelitis (VEE) virus to determine cross-protective immunity. Challenge infection produced 90% mortality in control (nonimmunized) equids, and 40% mortality in WEE virus-seropositive equids; all EEE virus-seropositive equids survived. Postchallenge exposure VEE viremia levels in EEE virus- or WEE virus-seropositive equids were lower than those in the 10 nonimmunized VEE virus-inoculated control equids. Plaque-neutralizing antibody responses to VEE virus in the EEE virus- and WEE virus-seropositive equids were similar in time of onset and titer to the antibody responses of nonimmunized equids. Neutralizing antibody to the third equine encephalomyelitis virus (either EEE virus or WEE virus) was detectable in 19 of 27 equids after inoculation with the challenge virus, VEE. Demonstration of cross-protective immunity between EEE or WEE virus and VEE virus in equids confirmed field observations made during the VEE epizootic in Texas in 1971.

AU - Zhang TS
TI - [A survey of antibodies to arboviruses in residents in south-western part of Yunnan province]. [Chinese]
SO - Chung-Hua Liu Hsing Ping Hsueh Tsa Chih Chinese Journal of Epidemiology 1989 Apr;10(2):74-7
AB - In order to provide serological evidence for arbovirus infection in Yunnan province, 760 Samples of human sera collected from nine counties in south-western part of Yunnan province were examined for HI antibodies to 11 arboviral antigens. The viruses used in this experiment included 3 alphaviruses (MAY, VEE and CHIK) and 8 flaviviruses (JE, MVE, KUN, DEN3, DEN4, KFD, LGT and POW). 275 samples were found positive for HI antibodies to alphaviruses (36.2%) and 189 of them (68.7%) reacted with MAY virus, 61 (22.2%) with CHIK. The GMT of HI titers for VEE, MAY and Chik were 164.4, 94.5 and 66.7, respectively. 588 samples of sera (77.4%) were found positive for HI antibodies to flaviviruses. The positive HI antibody rates were as follows: JE, 27.9%; DEN, 36.6%; KFD, 22.2%; MVE, 22.1%; KUN, 18.7%; POW, 8.8% and LGT, 7.9%, respectively. Its average GMT was 356, and the antibody titers of 403 samples of sera were higher than 1/640. Cross reactions among viruses, especially flaviviruses, were usually found by HI test, and superinfections were present. In addition to the existence of JE and DEN viruses the results clearly showed that many Kinds of arboviruses might exist in Yunan Province.

AU - Campbell J, Aldred J, Davis G
TI - Isolation of Ross River virus from Aedes camptorhynchus [letter].
SO - Medical Journal of Australia 1989 May 15;150(10):602-4

AU - Broom AK, Wright AE, MacKenzie JS, Lindsay MD, Robinson D
TI - Isolation of Murray Valley encephalitis and Ross River viruses from Aedes normanensis (Diptera: Culicidae) in Western Australia.
SO - J. Med. Entomol. 1989 Mar;26(2):100-3
AB - Of eight viruses isolated from 28,909 female (643 pools) Aedes normanensis collected from the north of Western Australia, two were identified as Murray Valley encephalitis virus and six as Ross River virus. The two isolates of Murray Valley encephalitis virus represent the first confirmed isolations of this virus from an Aedes species. The possible implications of these findings with regard to virus survival mechanisms during the dry season are discussed.

AU - Mezencio JM, de Souza W, Fonseca ME, Rebello MA
TI - Replication of Mayaro virus in Aedes albopictus cells: an electron microscopic study.
SO - Arch. Virol. 1989;104(3-4):299-308
AB - The replication of Mayaro virus in Aedes albopictus cells, was studied by electron microscopy at various times post-infection. In infected cells we observed the presence of cytoplasmic vesicles containing viral nucleocapsids and mature virus particles but at no time did we detect virus budding into such vacuoles. Budding of virus through plasma membrane was rarely observed. Our results are discussed considering the possibility of the release of virus particles to the extracellular space by exocytosis.

AU - Weaver SC, Scott TW, Lorenz LH, Lerdthusnee K, Romoser WS
TI - Togavirus-associated pathologic changes in the midgut of a natural mosquito vector.
SO - J. Virol. 1988 Jun;62(6):2083-90
AB - Arthropod-borne viruses were not previously believed to cause discernible pathologic changes in their natural mosquito vectors. We report cytopathologic lesions in the midgut of the mosquito, Culiseta melanura, 2 to 5 days after oral infection with eastern equine encephalomyelitis virus. Sloughing of densely staining, heavily infected epithelial cells into the midgut lumen was observed by light and transmission electron microscopy, along with degeneration of cells within the epithelium. Pathological changes in midgut epithelial cells sometimes included loss of brush border and basal lamina integrity. Disruption of the midgut basal lamina could result in bypassing of barriers to virus dissemination within the mosquito and allow rapid transmission to occur. Alternatively, luminal sloughing of heavily infected midgut epithelial cells may serve to modulate mosquito infections. These findings challenge previous beliefs regarding the benign nature of arbovirus-invertebrate host relationships.

AU - Olaleye OD, Omilabu SA, Fagbami AH
TI - Igbo-Ora virus (an alphavirus isolated in Nigeria): a serological survey for haemagglutination inhibiting antibody in humans and domestic animals.
SO - Trans. R. Soc. Trop. Med. Hyg. 1988;82(6):905-6
AB - Sera from humans and animals were tested for antibodies to Igbo-Ora virus by the haemagglutination-inhibition test. Prevalence in the human population (3.6%) was lower than that in the animal population (24.5%) in the same locality. No antibodies were detected in persons less than 20 years of age; the highest prevalence of antibodies was found in those above 40 years old. Among the animal species examined, cattle showed the highest prevalence (40%) of antibodies to Igbo-Ora virus. The potential hazard of the virus to human health is discussed.

AU - Woodruff PW, Morrill JC, Burans JP, Hyams KC, Woody JN
TI - A study of viral and rickettsial exposure and causes of fever in Juba, southern Sudan.
SO - Trans. R. Soc. Trop. Med. Hyg. 1988;82(5):761-6
AB - Patients presenting at the Juba Teaching Hospital, either with fever of undetermined origin or with a clinical cause of fever, gave evidence of exposure to a wide range of viral and rickettsial agents. Serological tests showed high antibody levels to flaviviruses (56.9%) and alphaviruses (29.2%), with lesser levels of bunyamweraviruses (3.8%), Rift Valley fever (2.3%), and sandfly fever (0.75%). Flavivirus exposure was significantly associated with clinical evidence of liver disease; repeated exposure to flaviviruses was particularly prevalent in those with poor sanitation and who had received previous injections. A significant focus of Ebola and Marburg exposure in Juba has been identified. Clinical evidence of liver disease was evident in 37% of patients studied, and 24.6% were HBsAg positive. The first 2 HIV-positive individuals from the southern Sudan are reported, including one with clinical AIDS. A high prevalence of positive antibodies to Rickettsia typhi in the population indicated that murine typhus was common locally. This study indicates the need for further public health measures in the southern Sudan to control the spread of these infections.

AU - Lvov DK, Vladimirtseva EA, Butenko AM, Karabatsos N, Trent DW, Calisher CH
TI - Identity of Karelian fever and Ockelbo viruses determined by serum dilution-plaque reduction neutralization tests and oligonucleotide mapping.
SO - Am. J. Trop. Med. Hyg. 1988 Dec;39(6):607-10
AB - The causative agents of Ockelbo disease in Sweden, Pogosta disease in Finland, and Karelian fever in the USSR have been attributed to alphaviruses (family Togaviridae) related to Sindbis virus. We compared prototypes Sindbis, Ockelbo, and Karelian fever viruses by neutralization tests. We also analyzed oligonucleotide fingerprint maps of prototypes Ockelbo and Karelian fever viruses and a strain of Sindbis virus from Czechoslovakia. The results indicate that Ockelbo and Karelian fever viruses are essentially identical and suggest that Ockelbo disease, Pogosta disease, and Karelian fever are synonyms for the same disease.

AU - Karabatsos N, Lewis AL, Calisher CH, Hunt AR, Roehrig JT
TI - Identification of Highlands J virus from a Florida horse [published erratum appears in Am J Trop Med Hyg 1989 Mar;40(3):228].
SO - Am. J. Trop. Med. Hyg. 1988 Dec;39(6):603-6
AB - A virus, strain 64A-1519, isolated from the brain of a horse dying of encephalitis in Florida in 1964, was identified as western equine encephalomyelitis (WEE) virus. Recently, we used polyclonal and monoclonal immune reagents to identify this isolate by comparing it to 2 strains of WEE virus and to Highlands J (HJ) virus in hemagglutination-inhibition, immunofluorescent antibody, and plaque-reduction neutralization tests. These tests demonstrate that strain 64A-1519 is a strain of HJ virus distinct from WEE virus.

AU - Burness AT, Pardoe I, Faragher SG, Vrati S, Dalgarno L
TI - Genetic stability of Ross River virus during epidemic spread in nonimmune humans.
SO - Virology 1988 Dec;167(2):639-43
AB - We have examined the rate of evolution of Ross River virus, a mosquito-borne RNA virus, during epidemic spread through tens of thousands of nonimmune humans over a period of 10 months. Two regions of the Ross River virus genome were sequenced: the E2 gene (1.2 kb in length), which encodes the major neutralization determinant of the virus, and 0.4 kb of the 3'-untranslated region. In the E2 gene, a single nucleotide change was selected which led to a predicted amino acid change at residue 219. No changes were selected in the 3'-untranslated region. By comparison with rates of evolution reported for non-arthropod-borne RNA viruses, the rate for Ross River virus is surprisingly low. We identify three features of the Ross River virus replication and transmission cycle which may limit the rate of evolution of arthropod-borne viruses in the field.

AU - Anonymous
TI - [Alphaviruses--a new vector expressing heterologous genes (editorial)]. [RUSSIAN]
SO - Voprosy Virusologii 1988 Jul-Aug;33(4):502-4

AU - Scott TW, Olson JG, All BP 3d, Gibbs EP
TI - Detection of eastern equine encephalomyelitis virus antigen in equine brain tissue by enzyme-linked immunosorbent assay.
SO - American Journal of Veterinary Research 1988 Oct;49(10):1716-8
AB - Sensitivity and specificity of an antigen-capture ELISA vs virus isolation in cell culture were evaluated for the detection of eastern equine encephalomyelitis (EEE) virus in the brain tissue of naturally infected equids. Brain specimens from 16 equids with neurologic disease were examined by ELISA and by inoculation onto baby hamster kidney cell cultures. Of 10 brain samples from which virus was isolated in the cell culture bioassay, all were correctly identified as containing EEE virus antigen by ELISA. None of the remaining 6 specimens, without detectable infectious EEE virus, contained detectable antigen. Sensitivity and specificity of the ELISA were 100% with no false-positive or false-negative results. The antigen-capture ELISA was a rapid, sensitive, specific, and simple alternative to a traditional bioassay for the detection of EEE virus.

AU - Kumanomido T, Kamada M, Wada R, Kenemaru T, Sugiura T, Akiyama Y
TI - Pathogenicity for horses of original Sagiyama virus, a member of the Getah virus group.
SO - Veterinary Microbiology 1988 Aug;17(4):367-73
AB - Sagiyama virus is a member of the Getah virus group. Its pathogenicity for horses was examined. All the horses infected with the original 4 strains of Sagiyama virus (M6/Mag 33, Mag 121, Mag 132 and Mag 258) developed pyrexia ranging from 39.0 to 40.0 degrees C. Other clinical signs, characterized by eruptions, edema in the hind legs, enlargement of the submandibular lymph node and mild leukopenia, were also manifested. Viremia occurred 1-4 days post-inoculation (p.i.). Virus was recovered from spleen, liver, lung and various lymph nodes of a horse autopsied on Day 4 p.i. The maximum titer of virus (10(6.0) TCID50 g-1) was detected in the inguinal lymph node. Seroconversion was demonstrated in all the infected horses on Day 5 p.i. These clinical signs and virological findings were similar to those of horses infected naturally. The results indicate that Sagiyama virus has pathogenicity for horses and is similar to that of Getah virus.

AU - Kumanomido T, Wada R, Kanemaru T, Kamada M, Hirasawa K, Akiyama Y
TI - Clinical and virological observations on swine experimentally infected with Getah virus.
SO - Veterinary Microbiology 1988 Mar;16(3):295-301
AB - The pathogenicity of Getah virus for swine was examined. All 8 pigs (4 adults and 4 piglets) inoculated with Strains MIP-99 and MI-110 developed pyrexia ranging from 39.4 to 40.7 degrees C and anorexia. Mild depression and diarrhea were observed in 2 of the 4 piglets. These clinical signs were transient. Viremia occurred 1-2 days post-inoculation (p.i.) and the maximum titer was 10(3.0) TCID50 0.1 ml-1. The virus was recovered from a piglet autopsied on Day 3 p.i. from spleen and various lymph nodes. The maximum titer of virus (10(3.75) TCID50 0.1 g-1) was detected in the inguinal lymph node. Seroconversion was demonstrated in all the pigs on Day 6 p.i. These results suggest that Getah virus is mildly pathogenic for swine, which may play a role as an amplifying host in nature.

AU - Kumanomido T, Wada R, Kanemaru T, Kamada M, Akiyama Y, Matumoto M
TI - Transplacental infection in mice inoculated with Getah virus.
SO - Veterinary Microbiology 1988 Feb;16(2):129-36
AB - Transplacental transmission was demonstrated in pregnant mice subcutaneously inoculated with Getah virus. Viremia was shown in the infected dams, and high-titered virus was detected in the placenta and later in the fetus, suggesting virus invasion of the fetus through hematogenous infection of the placenta. High-titered virus was shown in the fetal brain and muscle and in the brain of the young dying soon after birth. Intrauterine infection resulted in a reduction of the litter size, number of young born alive and survival rate to 1 week of age. These results were further corroborated by necropsy performed several days after virus inoculation. The stage of gestation at the time of virus inoculation greatly influenced these results. Dams inoculated at 12 days of gestation delivered all dead babies, whereas virus inoculation at 5 days of gestation had no effect on the number of young born alive. The dams inoculated at 8 days of gestation had reduced litter sizes and those inoculated at 16 days of gestation produced slightly fewer live babies. Gestational stage at the time of virus inoculation also influenced viral growth in fetuses and placentas. The infection rate was low in dams inoculated at 5 days of gestation, high in dams inoculated at 8 or 16 days of gestation and 100% in dams inoculated at 12 days of gestation. High-titered virus was shown in placentas and fetuses of the dams inoculated at 8, 12 or 16 days of gestation. These results suggest that Getah virus may readily cross the placental barrier through hematogenous infection of the placenta in mice.

AU - Calisher CH, Karabatsos N, Lazuick JS, Monath TP, Wolff KL
TI - Reevaluation of the western equine encephalitis antigenic complex of alphaviruses (family Togaviridae) as determined by neutralization tests.
SO - Am. J. Trop. Med. Hyg. 1988 Mar;38(2):447-52
AB - Fourteen viruses closely related to the Fleming strain of western equine encephalitis (WEE) virus were cross-tested by serum dilution-plaque reduction neutralization. The results demonstrate that strains McMillan, R-43738, AG80-646, BeAr 102091, and Y62-33 are subtypes or varieties of western equine encephalitis virus strain Fleming. Ockelbo, Kyzylagach, and Babanki are subtypes of the prototype strain (EgAr 339) of Sindbis virus. Fort Morgan and Buggy Creek viruses are closely related to each other, whereas Highlands J and Aura viruses are distinct from other members of this antigenic complex. There appear to be parallels between geographic distribution and antigenic relatedness. We hypothesize that birds, the principal vertebrate hosts for these viruses, spread the progenitor viruses north and south and from continent to continent. Viruses of the WEE complex with lesser antigenic differences may develop in discrete ecologic conditions.

AU - Main AJ, Anderson KS, Maxfield HK, Rosenau B, Oliver C
TI - Duration of Alphavirus neutralizing antibody in naturally infected birds.
SO - Am. J. Trop. Med. Hyg. 1988 Jan;38(1):208-17
AB - Native birds, mostly passerine species, ecologically associated with Culiseta melanura, the enzootic vector of eastern equine encephalomyelitis and Highlands J viruses in the eastern United States, were examined over a 12-year period in southeastern Massachusetts. These studies concentrated on those individual birds known, by banding returns, to be residents of large wooded swamps where both eastern equine encephalomyelitis and Highlands J viruses were known to be enzootic. Of 8,417 birds sampled, 1,227 (14.6%) were recaptured one or more times (mean 2.7 times). Antibody profiles on individuals nesting or feeding in enzootic areas were determined from serial blood samples drawn from these recaptured birds. The duration of detectable neutralizing antibody in these birds was found to be ephemeral in some species (e.g., black-capped chickadees) and extremely longlasting in others (e.g., gray catbirds, swamp sparrows). The significance of these findings to arbovirus surveillance programs is discussed.

AU - Oprandy JJ, Olson JG, Scott TW
TI - A rapid dot immunoassay for the detection of serum antibodies to eastern equine encephalomyelitis and St. Louis encephalitis viruses in sentinel chickens.
SO - Am. J. Trop. Med. Hyg. 1988 Jan;38(1):181-6
AB - A dot enzyme-linked immunosorbent assay utilizing a novel membrane, polyvinylidene difluoride, is described. This assay was developed for the rapid detection of serum antibodies to eastern equine encephalomyelitis virus and St. Louis encephalitis virus in sentinel chickens. Antigens were spot-filtered through the membrane. Membranes were dipped into small vials of sera. Antigen-antibody complexes were detected with enzyme-conjugated antiglobulin which, when exposed to substrate, produced a colored insoluble product. The antibody detection protocol was completed within 50 min and was compared with a standard plate enzyme immunoassay. Chickens were experimentally infected with eastern equine encephalomyelitis and St. Louis encephalitis and bled on a daily basis. The dot immunoassay correctly identified 99% (123/124) of the eastern equine encephalomyelitis virus and 100% (67/67) of the St. Louis encephalitis virus antisera. Sera from sentinel chicken flocks in Maryland were also assayed. These data indicate that the dot immunoassay should be considered as an alternative to current assays for the screening of sera for antibodies to virus antigens. This assay could easily be performed in the field and allows for the screening of antibodies to several different viruses in one test.

AU - Boughton CR, Hawkes RA, Naim HM
TI - Illness caused by a Barmah Forest-like virus in New South Wales.
SO - Medical Journal of Australia 1988 Feb 1;148(3):146-7
AB - Barmah Forest virus, a recently-discovered arbovirus which belongs to the alphavirus genus of the family Togaviridae, has been shown to cause infections in humans in New South Wales. The present report documents three patients in whom Barmah Forest viral infection appears to have resulted in illness. Barmah Forest virus or a closely-related alphavirus may, as are several other alphaviruses, be pathogenic.

AU - Scott TW, Olson JG, Lewis TE, Carpenter JW, Lorenz LH, Lembeck LA, Joseph SR, Pagac BB
TI - A prospective field evaluation of an enzyme immunoassay: detection of eastern equine encephalomyelitis virus antigen in pools of Culiseta melanura.
SO - Journal of the American Mosquito Control Association 1987 Sep;3(3):412-7
AB - A prospective field study was conducted to determine the sensitivity and specificity of an enzyme immunoassay (EIA) compared to virus isolation in cell culture for the detection of eastern equine encephalomyelitis (EEE) virus in naturally infected mosquitoes. A total of 10,811 adult female Culiseta melanura were collected in light traps during 1985 from four locations in Maryland. Eastern equine encephalomyelitis virus was isolated from 5 of 495 mosquito pools in African green monkey kidney and baby hamster kidney cell cultures. All five virus-infected pools were detected by the EIA, and all 490 uninfected pools were correctly scored as not containing virus. The EIA did not produce false positive or false negative results. Results support the assertion of previous researchers that the antigen detection EIA is a rapid, sensitive, specific, and simple alternative to traditional bioassays for the detection of EEE virus in mosquitoes.

AU - Rosen L
TI - Overwintering mechanisms of mosquito-borne arboviruses in temperate climates. [Review]
SO - Am. J. Trop. Med. Hyg. 1987 Nov;37(3 Suppl):69S-76S
AB - It can be concluded from the data cited that transovarial transmission is a plausible explanation for the overwintering of mosquito-borne bunyaviruses of the California serogroup. Vertical transmission of mosquito-borne flaviviruses could explain the overwintering of this group of viruses, but this is far from having been established. At present, the mechanism by which mosquito-borne alphaviruses pass the winter is obscure. [References: 62]

AU - Chang GJ, Trent DW
TI - Nucleotide sequence of the genome region encoding the 26S mRNA of eastern equine encephalomyelitis virus and the deduced amino acid sequence of the viral structural proteins.
SO - J. Gen. Virol. 1987 Aug;68 ( Pt 8):2129-42
AB - The 26S mRNA and most of the nsP4 encoding regions of the eastern equine encephalomyelitis (EEE) viral genome have been cloned. Excluding the poly(A) tail, the 26S mRNA region was determined to be 4139 nucleotides long and to share the same general organization as that of other alphaviruses. A highly conserved region of 19 nucleotides, the putative transcriptase recognition site for 26S mRNA synthesis, was present at the 26S/42S junction region of the 42S genomic RNA. Translation of the 26S mRNA began at the first AUG (positions 59 to 61) initiation codon and continued with an open reading frame that coded for a polyprotein of 1258 amino acids ending at a UAA ochre termination codon (positions 3776 to 3778). All four putative posttranslational cleavage sites used to generate the capsid, E3, E2, 6K and E1 proteins were conserved. Transmembrane domains present in the EEE virus structural polyprotein have been identified and their functions discussed. Pairwise comparison of the deduced amino acid sequences of the polyproteins of five alphaviruses (EEE, Venezuelan equine encephalitis, Sindbis, Semliki Forest and Ross River viruses) revealed EEE virus to be more closely related to VEE virus than to the other three viruses.

AU - Watts DM, Clark GG, Crabbs CL, Rossi CA, Olin TR, Bailey CL
TI - Ecological evidence against vertical transmission of eastern equine encephalitis virus by mosquitoes (Diptera: Culicidae) on the Delmarva Peninsula, USA.
SO - J. Med. Entomol. 1987 Jan;24(1):91-8

AU - Mitchell CJ, Miller BR, Gubler DJ
TI - Vector competence of Aedes albopictus from Houston, Texas, for dengue serotypes 1 to 4, yellow fever and Ross River viruses.
SO - Journal of the American Mosquito Control Association 1987 Sep;3(3):460-5
AB - A combination of virus infection and transmission experiments showed that a Houston, Texas strain of Aedes albopictus is a competent vector for dengue (DEN), yellow fever (YF) and Ross River (RR) viruses. However, at 14 days incubation, DEN virus infection rates in a Puerto Rican strain of Aedes aegypti were significantly higher for each of the four DEN serotypes, except DEN-1, than in Houston Ae. albopictus fed simultaneously on the same virus suspensions. The degree of correlation between disseminated DEN infection rates in Houston Ae. albopictus and transmission to an in vitro system ranged from 42 to 88% for the four DEN serotypes. No significant difference was noted in YF virus infection rates or transmission rates in the two mosquito species fed on the same virus suspensions and incubated for the same time period. Also, RR virus infection and transmission rates in Houston and Hawaiian strains of Ae. albopictus were generally comparable.

AU - Carvalho MG, Rebello MA, Mezencio JM
TI - Effect of high temperature on Aedes albopictus cells infected with Mayaro virus.
SO - Brazilian Journal of Medical & Biological Research 1987;20(6):857-60
AB - The multiplication of Mayaro virus in Aedes albopictus cells was drastically inhibited after incubation at 37 degrees C. The effect of short-term exposure of infected cells to high temperatures (heat shock) produced a preferential translation of the heat shock messengers when compared to the viral mRNAs. When cells were shifted back to 28 degrees C (the optimum growth temperature for Aedes albopictus cells), preferential translation of viral mRNA occurred. Although the infected cells were programmed for preferential translation of viral messengers, the thermal treatment was able to shift the translational machinery towards synthesis of heat shock proteins.

AU - Scrimgeour EM, Aaskov JG, Matz LR
TI - Ross River virus arthritis in Papua New Guinea.
SO - Trans. R. Soc. Trop. Med. Hyg. 1987;81(5):833-4
AB - In 1975 it was reported that antibodies to Ross River virus (RRV) were present in the sera of many population groups in Papua New Guinea. We describe here 3 cases of polyarthritis that occurred in Port Moresby, the capital of Papua New Guinea, during 1980-81 and in which the diagnosis of RRV infection was confirmed by serological tests, and 3 other cases in which serological tests suggested RRV infection but were not diagnostic. A possible case of fatal RRV encephalitis is also reported.

AU - Liu TH, Chen WF
TI - Susceptibility of mammalian cell cultures to infection with arbo-togaviruses.
SO - Chung-Hua Min Kuo Wei Sheng Wu Chi Mien i Hsueh Tsa Chih - Chinese Journal of Microbiology & Immunology 1987 Nov;20(4):349-55
AB - Six alphaviruses and four flaviviruses were inoculated intracerebrally into 1 to 3 days old suckling mice. All mice developed CNS diseases and died 2-5 days post-infection. It appeared that alphaviruses were more virulent than flaviviruses since they brought death to the injected mice earlier than the flaviviruses. The susceptibilities of nine different culture cells to those viruses were also investigated using plaque assay. BHK-21 cells produced clearer plaques and were more sensitive than other cells. Plaque reduction tests using antibodies against various viruses revealed no cross-reactions between alphavirus and flavivirus. However, minor cross-reactions were found within groups. The results of this study suggest that BHK-21 cells can be used for the large scale screening of viruses in domestic animal specimens and for detecting serum neutralizing antibodies against arboviruses.

AU - Carter IW, Fraser JR, Cloonan MJ
TI - Specific IgA antibody response in Ross River virus infection.
SO - Immunology & Cell Biology 1987 Dec;65 ( Pt 6):511-3
AB - Sera were collected over a period of several years from the onset of initial symptoms from 77 patients with Ross River virus infection. When tested for virus-specific IgA antibodies, using an enzyme-linked immunosorbent assay (ELISA) based on antibody class capture, 245 out of 704 sera were antibody-positive. Although Ross River virus IgA antibodies were present in the serum of all patients soon after onset of symptoms, the IgA response was relatively short-lived in comparison with specific IgM antibodies. The results suggested that the detection of high levels of Ross River virus IgA antibodies was of potential value in differentiating between recent and past infection, especially in those patients with persisting IgM antibodies.

AU - Yago K, Hagiwara S, Kawamura H, Narita M
TI - A fatal case in newborn piglets with Getah virus infection: isolation of the virus.
SO - Nippon Juigaku Zasshi - Japanese Journal of Veterinary Science 1987 Dec;49(6):989-94

AU - Clark GG, Dein FJ, Crabbs CL, Carpenter JW, Watts DM
TI - Antibody response of sandhill and whooping cranes to an eastern equine encephalitis virus vaccine.
SO - Journal of Wildlife Diseases 1987 Oct;23(4):539-44
AB - As a possible strategy to protect whooping cranes (Grus americana) from fatal eastern equine encephalitis (EEE) viral infection, studies were conducted to determine the immune response of this species and sandhill cranes (Grus canadensis) to a formalin-inactivated EEE viral vaccine. Viral-specific neutralizing antibody was elicited in both species after intramuscular (IM) vaccination. Subcutaneous and intravenous routes of vaccination failed to elicit detectable antibody in sandhill cranes. Among the IM vaccinated cranes, the immune response was characterized by nondetectable or low antibody titers that waned rapidly following primary exposure to the vaccine. However, one or more booster doses consistently elicited detectable antibody and/or increased antibody titers in the whooping cranes. In contrast, cranes with pre-existing EEE viral antibody, apparently induced by natural infection, exhibited a rapid increase and sustained high-antibody titers. Even though EEE virus vaccine induced neutralizing antibody and produced no adverse side effects, further studies will be required to determine the protective efficacy of the antibody.

AU - Hawkes RA, Boughton CR, Naim HM, Myrick BA, Ramsay LG
TI - Barmah Forest virus infections in humans in New South Wales.
SO - Medical Journal of Australia 1987 Jun 1;146(11):569-73
AB - Antibodies to Barmah Forest virus, a member of the alphavirus group, which was first isolated in 1974, have been found to be widespread in humans in New South Wales. Antibody studies showed a higher prevalence in the north coastal zones of the State, and lower rates in individuals who were living in all other biophysical zones. Antibody rates were significantly higher in male than in female subjects. The pathogenicity of the Barmah Forest virus is at present not known.

AU - Rodhain F, Carteron B, Laroche R, Hannoun C
TI - [Human arbovirus infections in Burundi: results of a seroepidemiologic survey, 1980-1982]. [French]
SO - Bulletin de la Societe de Pathologie Exotique et de Ses Filiales 1987;80(2):155-61
AB - A serological survey on 623 human sera was conducted in Burundi in 1980-1982, in order to evaluate the frequency of arboviral antibodies in the inhabitants of the three main areas: lowlands, central plateau and mountainous ridge. The results show a rather high activity of arboviruses, mainly in the lowlands (34.2% of inhabitants with antibodies). Chikungunya virus seems to be the most active arbovirus; the activity of Flavivirus is moderate; no trace of activity of yellow fever or West Nile viruses was found; Bunyavirus antibodies (particularly against Ilesha virus) were also detected.

AU - Kay BH, Pollitt CC, Fanning ID, Hall RA
TI - The experimental infection of horses with Murray Valley encephalitis and Ross River viruses.
SO - Australian Veterinary Journal 1987 Feb;64(2):52-5
AB - Eleven weanling horses were inoculated with Murray Valley encephalitis and Ross River viruses either by intravenous injection or by the bite of Culex annulirostris or Aedes vigilax mosquitoes infected orally. Five of the 11 horses circulated trace amounts of MVE virus for 1 to 5d and they infected 7/408 Cx annulirostris which subsequently fed on them. Haemagglutination-inhibiting antibody persisted at detectable levels for the 24-week observation period. With Ross River virus, only one of 11 horses inoculated developed a viraemia detectable by inoculation of suckling mice but 5 horses contained virus sufficient to infect 41/383 Cx annulirostris that fed on them 3 to 4 days after inoculation. On primary inoculation with Ross River virus, only 2 horses developed HI antibody but late responses occurred in 3 horses following probable naturally acquired re-infections. With both viruses, most horses remained normal, some developed mild pyrexia and transient clinical signs. This paper, therefore, indicates that horses are unlikely to be efficient amplifiers of either MVE or RR viruses and does little to incriminate them as important pathogens.

AU - Morier L, Cantelar N, Soler M
TI - Infection of a poikilothermic cell line (XL-2) with eastern equine encephalitis and western equine encephalitis viruses.
SO - J. Med. Virol. 1987 Mar;21(3):277-81
AB - Eastern Equine Encephalitis (EEE) was in Cuba before the 1940s; the virus has been isolated from horses, birds, and rodents during epizootic as well as interepizootic periods. The only isolation of Western Equine Encephalitis (WEE) virus was from a sick pigeon found in the vicinity of Havana University. Both viruses can cause human disease; the isolation of WEE virus from the centre of an urban area emphasises the need for the prompt isolation and rapid identification of these agents. The object of this work was to compare the sensitivity of a continuous cell line (XL-2) from the toad, Xenopus laevis, with primary chick embryo cell cultures (CEC) routinely used for isolation as well as assay of these viruses. Both cell systems were infected with EEE virus isolated from horse brain and WEE virus isolated from a sick pigeon. A clear cytopathic effect (CPE) consisting of rounding and detachment of cells was observed in both cell cultures infected with the two viruses. By 18 hours post-infection, there was partial destruction of the cell monolayer and by 24 hours the CPE was total. The infectious titre of EEE and WEE viruses in XL-2 and CEC were similar. Both viruses produced small plaques (0.5-1.0 mm diameter) in XL-2 cells. Studies on the sensitivity of the XL-2 cells for direct isolation of the two viruses from field samples and for the detection of Cuban flaviviruses by the immunofluorescence test are in progress.

AU - Leake CJ, Ussery MA, Nisalak A, Hoke CH, Andre RG, Burke DS
TI - Virus isolations from mosquitoes collected during the 1982 Japanese encephalitis epidemic in northern Thailand.
SO - Trans. R. Soc. Trop. Med. Hyg. 1986;80(5):831-7
AB - From 16 June to 15 August, 1982 CDC light traps were used to collect mosquitoes in the province of Kamphaengphet, N. Thailand. 353,042 mosquitoes comprising 59 species were collected and identified, and 345,173 were placed in pools for attempted virus isolation by inoculation of C6/36 Aedes albopictus mosquito cell cultures. Viruses were isolated from 63 mosquito pools. These comprised 56 flaviviruses, identified as 35 isolates of Japanese encephalitis (JE) virus strains, 18 strains of Tembusu (TEM) virus and three untyped flaviviruses (FLA); three alphaviruses, identified as the first isolates of Getah (GET) virus to have been made in Thailand; and four viruses which are still unidentified. Most virus isolates were from Culex tritaeniorhynchus mosquitoes collected in carbon dioxide baited light traps. JE virus was isolated only over a ten-day period and the last isolate was obtained one week before the peak of admission of human encephalitis cases at Kamphaengphet Provincial Hospital. Rapid screening of isolates grown on Ae. pseudoscutellaris (LSTM-AP-61) mosquito cells by indirect immunofluorescence using flavivirus group-specific and JE-specific monoclonal antibodies showed a high degree of correlation with plaque reduction neutralization tests. An antigen capture enzyme immunoassay (EIA) test successfully identified about 50% of the JE virus positive pools, but the method saved considerable processing time.

AU - Xiao ZS, Jia LL, Qu XS, Zhang YH
TI - Application of enzyme immunoassay on infected cells (EIA-IC) for arboviruses.
SO - Acta Virologica 1986 Nov;30(6):487-93
AB - Comparative titrations of alpha-, flavi- and Bunyamwera viruses were made by EIA-IC and according to cytopathic effect (CPE). Specific enzymatic reactions appeared earlier and in higher titres than CPE. The titres of dengue type 1, Mayaro, Powassan and Langat viruses measured by EIA-IC were comparable to those measured by intracerebral inoculation of mice. The cross-reactivity testing of EIA-IC among alphaviruses (Chikungunya, Sindbis and Mayaro), flaviviruses (Japanese encephalitis, Murray valley encephalitis, Kunjin, West Nile, yellow fever and louping ill, Powassan, Langat) and Bunyamwera arboviruses using polyclonal immune ascitic fluids confirmed the high specificity of EIA-IC. Homologous reactions mostly showed higher titres than heterologous ones. No cross-reactivity was seen between alpha-, flavi- and bunyaviruses, among the three alphaviruses, between mosquito-borne and tick-borne flaviviruses, or between JE complex and YF viruses. However, a cross-reactivity to different extent was observed among the four JE complex viruses and among louping ill, Powassan and Langat viruses. The results of EIA-IC cross tests showed that this method can distinguish togavirus group- or species-specific antigens, more precisely than conventional ELISA.

AU - Srivastava AK, Igarashi A
TI - Structural proteins of Getah virus isolates from Japan and Malaysia.
SO - Acta Virologica 1986 Mar;30(2):126-30
AB - Purified preparations of Getah virus strains have been analysed by sodium-dodecyl-sulphate polyacrylamide gel electrophoresis (SDS-PAGE) to reveal their structural proteins. Two envelope proteins (E1 and E2) and core protein (C) were found with the prototype AMM2021 strain both under reducing and nonreducing conditions, while separation of E1 and E2 was observed only under nonreducing conditions for 3 strains isolated in Japan. Limited digestion by Staphylococcus aureus V8 protease revealed difference in the peptide patterns of E1 between AMM2021 and Japanese isolates. Mobility of E1 and E2 was slower for the virus grown in BHK21 cells compared with the virus grown in Aedes albopictus cells, indicating host-controlled modification on the envelope glycoproteins.

AU - Crans WJ, McNelly J, Schulze TL, Main A
TI - Isolation of eastern equine encephalitis virus from Aedes sollicitans during an epizootic in southern New Jersey.
SO - Journal of the American Mosquito Control Association 1986 Mar;2(1):68-72
AB - Eastern equine encephalitis virus (EEE) was isolated from the salt marsh mosquito, Aedes sollicitans, collected from coastal areas of New Jersey on 3 occasions during the late summer and fall of 1982. The isolations were made at a time when local Culiseta melanura were either undergoing a population increase or exhibiting high levels of EEE virus. Although no human cases were reported during the epizootic period, the data lend support to the hypothesis that Ae. sollicitans is capable of functioning as an epidemic vector in the coastal areas of New Jersey where human cases of EEE have been most common.

AU - Crans WJ
TI - Failure of chickens to act as sentinels during an epizootic of eastern equine encephalitis in southern New Jersey, USA.
SO - J. Med. Entomol. 1986 Dec 4;23(6):626-9

AU - McIntosh BM
TI - Mosquito-borne virus diseases of man in southern Africa. [Review]
SO - South African Medical Journal 1986 Oct 11;Suppl:69-72

AU - Calisher CH, Fremount HN, Vesely WL, el-Kafrawi AO, Mahmud MI
TI - Relevance of detection of immunoglobulin M antibody response in birds used for arbovirus surveillance.
SO - Journal of Clinical Microbiology 1986 Nov;24(5):770-4
AB - Young chickens were inoculated with 5,000 PFU of eastern equine encephalitis (EEE) virus and bled at intervals thereafter for determinations of hemagglutination-inhibiting (HI), neutralizing (N), immunoglobulin M (IgM), and IgG antibodies. HI, N, and IgM antibodies were first detected 4 days after infection, and IgG was detected 7 days after infection. All four antibodies persisted through day 90 after infection. HI, N, and IgM antibody titers remained elevated and were not cross-reactive with the related alphavirus western equine encephalitis (WEE) virus. IgG antibody titers also remained high, but heterologous reactivity to WEE virus increased with time after infection. Serum samples from sentinel chickens and wild birds infected in nature with EEE, WEE, or St. Louis encephalitis virus and submitted to this laboratory from state and local health departments were tested for IgM antibody by using anti-chicken IgM for capture and for IgG antibodies to the EEE and WEE viruses. There was essentially complete correlation between HI, N, and either IgM (indicating recent infections) or IgG (indicating more remote infections) antibody. We conclude that the IgM antibody capture enzyme immunoassay can be used as a specific and sensitive assay to replace the routinely used HI test for detecting antibody in sentinel chickens and in young, wild birds used for arbovirus surveillance. The test is rapid and relatively inexpensive and can be performed in essentially all adequately supplied laboratories.

AU - Van der Waals FW, Asher DM, Goudsmit J, Pomeroy KL, Karabatsos N, Gajdusek DC
TI - Post-encephalitic epilepsy and arbovirus infections in an isolated rainforest area of central Liberia.
SO - Tropical & Geographical Medicine 1986 Sep;38(3):203-8
AB - Among a population of 4.436 Bassa, Kpelle and Mano people in the Gbawein and Wroughbarh Clan region of Grand Bassa Country, Liberia, 123 cases of epilepsy could be documented. In 38% of these cases infections involving the central nervous system precipitated the onset of seizures. Sera from 67 epilepsy patients, 50 direct healthy relatives and 22 geographically matched controls were tested for antibodies to 16 arboviruses of the Togaviridae and Bunyaviridae known to occur in Africa. Antibodies to arboviruses were found in 16.5% of the epilepsy patients, 36% of the mostly older family members, and in 22% of the controls. Males and females were equally affected as were the different clans and language groups. Although meningoencephalitis with sequelae, like seizures, are known to result from arbovirus infections, no evidence for a correlation between epilepsy in this are of Central Liberia and previous arbovirus infection could be established.

AU - Kislenko GS, Chunikhin SP
TI - [Results of studying foci of arbovirus infections in the southern Maritime Territory]. [RUSSIAN]
SO - Meditsinskaia Parazitologiia i Parazitarnye Bolezni 1986 May-Jun;(3):68-74

AU - Ballard JW, Marshall ID
TI - An investigation of the potential of Aedes camptorhynchus (Thom.) as a vector of Ross River virus.
SO - Australian Journal of Experimental Biology & Medical Science 1986 Apr;64 ( Pt 2):197-200
AB - Aedes camptorhynchus (Thom.) collected on the mid-south coast of New South Wales during the winter of 1982 were highly susceptible to infection (ID50 = 10(2.4) VERO pfu/mosquito) when fed on rat tail skins containing blood and serial dilutions of the T48 strain of Ross River (RR) virus. After 2 d, when no virus was detectable, rapid proliferation allowed transmission from 5 d post ingestion. A maximum transmission rate occurred 9 d post-feeding when 4 of 4 infected mosquitoes transmitted virus. The susceptibility of Ae camptorhynchus to RR virus infection was compared with that of a laboratory colony of Ae aegypti (L.) (ID50 = 10(3.8) VERO pfu/mosquito).

AU - Scott TW, Olson JG
TI - Detection of eastern equine encephalomyelitis viral antigen in avian blood by enzyme immunoassay: a laboratory study.
SO - Am. J. Trop. Med. Hyg. 1986 May;35(3):611-8
AB - An enzyme immunoassay (EIA) was evaluated for its efficacy at detecting eastern equine encephalomyelitis (EEE) virus in avian blood and brain specimens. Preliminary analysis of blood from experimentally infected house sparrows and naturally infected whooping cranes showed that EEE antigen could be detected with the EIA. Polyclonal mouse antibodies were selected for antigen capture, and rabbit antibodies were selected for antigen detection. Overnight antigen incubation increased sensitivity. The lower limit of EEE antigen detection was 10(3.5) TCID50/ml for a stock of virus. Sensitivity was 10% (2/20) for antigen detection in the blood of chicks inoculated with EEE virus less than 24 hr earlier. At 24 and 48 hr after infection, sensitivity was 100% (10/10). Sensitivity and specificity of antigen detection were excellent (100% for both) in house sparrows experimentally inoculated with EEE, Highlands J (HJ), western equine encephalomyelitis (WEE), or St. Louis encephalitis (SLE) virus and bled at 24 hr intervals. Cross-reactivity was observed, however, with high concentrations (10(5.5) TCID50/ml) of HJ virus. EEE antigen was detected in avian blood by the EIA after infectious virus had declined to undetectable levels. The EIA is a useful alternative to virus isolation in cell culture for diagnosis or detection of EEE virus infections in birds. The test has the advantages of being simple, rapid, and capable of detecting antigen in the absence of infectious virus.

AU - Calisher CH, Berardi VP, Muth DJ, Buff EE
TI - Specificity of immunoglobulin M and G antibody responses in humans infected with eastern and western equine encephalitis viruses: application to rapid serodiagnosis.
SO - Journal of Clinical Microbiology 1986 Feb;23(2):369-72
AB - Paired sera from 20 humans with eastern equine encephalitis (EEE) virus infections and from 17 humans with western equine encephalitis (WEE) virus infections, all with previously demonstrated fourfold or greater rises or falls in hemagglutination-inhibiting, complement-fixing, or neutralizing antibody titers, were tested for immunoglobulin M (IgM) and IgG antibodies by an enzyme immunoassay. All individuals with EEE and 14 of 17 individuals with WEE had IgM antibody, some as early as 1 day after onset. Two of the three persons with WEE who did not develop IgM antibody died. IgM antibody declined but persisted for at least 3 months after the onset of illness in one individual each with EEE and WEE. IgG antibody was not detected until the middle of week 2 after onset. The sensitivity of the IgM antibody capture enzyme immunoassay described and the specificity, as shown by the absence of heterologous alphavirus reactivity, indicate that this is the test of choice for the rapid diagnosis of human infections caused by EEE and WEE viruses.

AU - Calisher CH, el-Kafrawi AO, Al-Deen Mahmud MI, Travassos da Rosa AP, Bartz CR, Brummer-Korvenkontio M, Haksohusodo S, Suharyono W
TI - Complex-specific immunoglobulin M antibody patterns in humans infected with alphaviruses.
SO - Journal of Clinical Microbiology 1986 Jan;23(1):155-9
AB - Sera from humans with serologically confirmed eastern equine encephalitis, western equine encephalitis, Pogosta (Ockelbo), Mayaro, Ross River, and chikungunya virus infections were tested by immunoglobulin M (IgM) antibody capture enzyme immunoassay. Diagnostically useful IgM antibody titers were detected, and selected sera with high IgM antibody titers were tested for IgM antibody with nine heterologous alphaviruses. The results provide evidence for the complex specificity of IgM antibody and indicate the usefulness of this test in both individual cases and epidemic situations.

AU - Liprandi F, Gomez B, Walder R
TI - Replication of alphaviruses in cultures of donkey monocytes.
SO - Arch. Virol. 1986;87(3-4):163-71
AB - Representative strains of Venezuelan equine encephalitis virus (VEEV) and Eastern equine encephalitis virus (EEEV) were compared for their ability to grow in cultures of unstimulated leucocytes and monocytes derived from donkey peripheral blood. Replication of epizootic and vaccine strains of VEEV, but not of enzootic strains was observed in this system. Only a minority of monocytes supported virus replication as detected by immunofluorescence, electron microscopy and infectious center assays. EEEV did not appear to replicate in this cell system although virus attached to and was internalized by monocytes.

AU - Mullbacher A, Marshall ID, Ferris P
TI - Classification of Barmah Forest virus as an alphavirus using cytotoxic T cell assays.
SO - J. Gen. Virol. 1986 Feb;67 ( Pt 2):295-9
AB - Barmah Forest virus, an arbovirus, does not cross-react convincingly with alpha-, flavi- or bunyavirus immune sera. Secondary cytotoxic T cells generated in vitro immune to a number of alphaviruses cross-lyse Barmah Forest virus-infected target cells. Flavivirus (West Nile and Kunjin)- and Bunyamwera virus-immune Tc cells lyse homologous virus-infected target cells, but not alphavirus-infected targets. Using cytotoxic T cell assays Barmah Forest virus can be classified as an alphavirus.

AU - Clark GG, Crans WJ, Crabbs CL
TI - Absence of eastern equine encephalitis (EEE) virus in immature Coquillettidia perturbans associated with equine cases of EEE.
SO - Journal of the American Mosquito Control Association 1985 Dec;1(4):540-2

AU - Faragher SG, Marshall ID, Dalgarno L
TI - Ross River virus genetic variants in Australia and the Pacific Islands.
SO - Australian Journal of Experimental Biology & Medical Science 1985 Aug;63 ( Pt 4):473-88
AB - HaeIII and TaqI restriction digest profiles of cDNA to infected cell RNA or virion RNA were used as a guide to genetic relationships between fourteen isolates of Ross River virus (RRV) obtained from mosquitoes collected in various localities in eastern Australia where the virus is endemic. RRV isolates from Fiji, American Samoa, the Cook Islands and the Wallis Islands where major outbreaks of epidemic polyarthritis took place in 1979-1980 were also examined. Among these RRV isolates we have identified three genetic types (I-III) on the basis of differences between their restriction digest profiles. We estimate that 1.5-5% nucleotide sequence diversity exists between genetic types. Within each genetic type strain differentiation gave rise to small but significant differences in restriction digest profiles. No clear pattern of geographic distribution of RRV genetic types could be established from the limited number of RRV isolates examined. Genetic types I, II and III, respectively, were isolated from three, three and one different mosquito species, indicating there is no strong association between genetic type and the species of mosquito vector. HaeIII restriction digest analysis did not detect any genetic difference between the four Pacific Island isolates, suggesting that a single RRV variant was involved in the epidemics. Genetically, this variant was closely related to isolates of genetic type II. Virtually identical HaeIII restriction digest profiles were observed for isolates obtained at various stages of the Pacific Island epidemics, suggesting that extensive sequence evolution did not accompany Ross River virus spread.

AU - Monath TP, Sabattini MS, Pauli R, Daffner JF, Mitchell CJ, Bowen GS, Cropp CB
TI - Arbovirus investigations in Argentina, 1977-1980. IV. Serologic surveys and sentinel equine program.
SO - Am. J. Trop. Med. Hyg. 1985 Sep;34(5):966-75
AB - Serologic surveys of wild and domestic birds, wild mammals, and horses were conducted during arbovirus field studies in Argentina from 1977 through 1980, a non-epizootic interval. The prevalence of neutralizing antibodies to eastern equine encephalitis (EEE) was consistently higher than to western equine encephalitis (WEE) virus in all species and all areas. The presence of antibodies in short-lived avian species and in young unvaccinated horses and the demonstration of seroconversions in horses during the period, indicated that these viruses are either enzootic in, or annually reintroduced into, Argentina. Antibodies to AG80-646, a new subtype of WEE virus isolated in the subtropical north (Chaco Province) from Culex (Melanoconion) mosqui