ECOLOGY OF JAMESTOWN CANYON VIRUS (BUNYAVIRIDAE, CALIFORNIA SEROGROUP) IN COASTAL CALIFORNIA

This paper reports the first isolation of Jamestown Canyon (JC) virus from coastal California and the results of tests for antibody to JC vi rus in mammals living in coastal California. The virus isolation was m ade from a pool of 50 Aedes dorsalis females collected as adults from Morro Bay, San Luis Obispo County, California. The virus isolate was i dentified by two-way plaque reduction-serum dilution neutralization te sts done in Vero cell cultures. Sera from the mammals were tested for antibody to JC virus by a plaque-reduction serum dilution neutralizati on method. A high prevalence of JC virus-specific antibody was found i n horses and cattle sampled from Morro Bay. This finding is additional evidence for the presence of a virus antigenically identical or close ly related to JC virus in Morro Bay and indicates that the vectors of the virus in Morro Bay feed on large mammals. A high prevalence of vir us-specific antibody was also found in horses sampled from Marin and S an Diego counties. This finding suggests that viruses antigenically id entical or closely related to JC virus are geographically widespread i n coastal California.