California Serogroup Viruses Research Articles

Enzyme-linked immunosorbent assay typing of California serogroup viruses isolated in Canada.

A procedure was developed to type California serogroup viruses by an antibody-capture, enzyme-linked immunosorbent assay. Seven California serogroup members from North America were distinguished, including snowshoe hare, La Crosse, California encephalitis, San Angelo, Jamestown Canyon, Keystone, and trivittatus. Extensive cross-reactions were observed between Jamestown Canyon and the closely related South River strain. The enzyme-linked immunosorbent assay method was successfully applied to the typing of 77 California serogroup viruses isolated in Canada, including 61 snowshoe hare, 13 Jamestown Canyon, and 3 trivittatus topotypes.

Human infections with La Crosse virus in Georgia, 1982.

Eight cases of central nervous system infection due to La Crosse (California serogroup) virus were detected in Georgia children in 1982. The patients were residents of the state, without histories of travel away from the vicinities of their homes during the 30 days before the onset of their illnesses. All were hospitalized with a diagnosis of aseptic meningitis or encephalitis; none had sequelae. Onset dates were from May 1 to Aug 30. Distribution of cases within the state suggested that active transmission of La Crosse virus occurred at least in the southeast quadrant of the state. The epidemiology and natural cycle of La Crosse in the southeastern United States are briefly discussed.

Book Review: California Serogroup Viruses

Book Review: California Serogroup Viruses

Serological evidence of infection with California serogroup viruses (family Bunyaviridae) in residents of Long Hua, suburb of Shanghai, People's Republic of China

Sera from 126 residents of Long Hua, a suburb of Shanghai, in the People's Republic of China, were studied. Sera were tested for haemagglutination inhibiting antibodies to alphavirus (eastern equine encephalitis, western equine encephalitis), flavivirus (St. Louis encephalitis, Powassan, dengue) and California serogroup (snowshoe hare) antigens. Flavivirus antibodies were found in 14 (11·1%) and California serogroup antibodies in 5 (3·9%) individuals. Neutralizing antibodies with highest titres to snowshoe hare virus were demonstrated in 3 of the 5 California serogroup reactors. We believe this to be the first report of California serogroup virus antibodies in Chinese residents and the first evidence to suggest that California serogroup viruses may be circulating in the Orient.

California Serogroup Viruses

California Serogroup Viruses

Arboviruses from western Utah, USA, 1967-1976.

An arbovirus survey was made of 7 areas in western Utah. From 215,150 pooled specimens of mosquitoes and the biting midge Culicoides variipennis, 307 arboviruses were isolated. One was an alphatogavirus (western equine encephalitis), 256 were California serogroup, and 50 were Bunyamwera serogroup (35 Main Drain, 9 Lokern, and 6 Cache Valley) viruses. Aedes dorsalis accounted for 47% of the total pooled specimens but represented 91% of all California serogroup viruses, 64% of which were from Blue Lake where Ae. dorsalis constituted 84% of the pooled mosquitoes. Ditto Dunes accounted for 66% of the Main Drain viruses, most of which were from Psorophora signipennis. Most Lokern viruses were from C. variipennis from Fish Springs and Callao, and most Cache Valley viruses were from Culiseta inornata from Hickman Canyon. Precipitin results on 347 blood-engorged mosquitoes and on the biting midge indicated that for all feedings, 47% were by Ae. dorsalis and 48% were on rabbits.

International symposium on california serogroup viruses

International symposium on california serogroup viruses

Characterization of monoclonal antibodies against the G1 and N proteins of LaCrosse and Tahyna, two California serogroup bunyaviruses

Antibody-secreting hybrid cell lines were isolated by fusion of spleen cells from BALB/c mice infected with LaCrosse and Tahyna viruses with mouse myeloma cells. Of 23 cell lines, 15 secreted immunoglobulins which precipitated the G1 envelope glycoprotein, and 8 secreted immunoglobulins which precipitated the nucleocapsid protein; none reacted with the two other virion proteins, G2 or L. Monoclonal antibodies were characterized in neutralization (N), hemagglutination inhibition (HI), and ELISA tests against 11 California serogroup viruses. (i) Antibodies against the G1 viral glycoprotein fell into four groups designated A, B, C, and D. Groups A and B antibodies had high N and HI titers; group A antibodies were virus specific while those in group B were cross-reactive with many California serogroup viruses. Groups C and D antibodies had no N or HI activity, with one exception which did not neutralize but had HI activity. Group C antibodies bound preferentially to the homologous virus, while group D antibodies were cross-reactive. The concordance of N and HI responses suggests that the viral glycoprotein has a single domain which binds to cellular receptors and that groups A and B monoclonal antibodies interfere with this function. (ii) Nucleocapsid antibodies showed neither N nor HI activity and fell into two groups, designated E and F; group E antibodies bound preferentially to the homologous virus, while group F antibodies were cross-reactive with other California serogroup viruses. (iii) Monoclonal antibodies can be used to rapidly determine the phenotype of reassortants between LaCrosse and Tahyna viruses, for two of three gene segments. (iv) The identification of specific shared and unshared antigenic determinants provides a much improved rationale for the serologic taxonomy of California viruses, and suggests possible revisions in existing classification. Use of selected monoclonal antibodies also markedly facilitates identification of virus isolates.

Virus isolations from mosquitoes in southern Ontario, 1976 and 1977.

Following the 1975 epidemic of St. Louis encephalitis (SLE) in Ontario, programs were instituted to monitor virus activity in mosquito populations during 1976 and 1977. Mosquitoes were trapped with CDC light traps and CO2 cone traps, pooled by species, and tested for virus by intracerebral inoculation of suckling mice. In 1976, 51 175 mosquitoes were tested. SLE virus was isolated from two mixed pools of Culex pipiens--C. restuans mosquitoes. Five isolations of California serogroup viruses were made. Three of these were trivittatus virus, which has not been demonstrated previously in Canada, and the other two were snowshoe have virus. Other viruses isolated in 1976 were a virus antigenically identical to the virus of infectious bursal disease of chickens and 34 Flanders viruses. In 1977, 34 428 mosquitoes were tested. Flanders virus was isolated most frequently, from pools of mixed C. pipiens--C. restuans mosquitoes. The only other isolate was a Bunyamwera group virus, Cache Valley virus. This virus has not been reported previously in Ontario.