An ecological study of Jamestown Canyon virus on the Delmarva Peninsula, with emphasis on its possible vector.

Abstract

An ecological study was conducted during 1983 and 1984 to evaluate the role of selected hematophagous arthropods as possible vectors and/or reservoirs of Jamestown Canyon (JC) virus on the Delaware-Maryland-Virginia Peninsula, USA. Arthropods were collected and assayed for virus in Vero cells by standard plaque technique. Sera from sentinel goats, free-ranging goats, and wild vertebrates were assayed for JC-virus-neutralizing (N) antibody by plaque-reduction neutralization tests. This virus was not isolated from 158,253 adult bloodsucking insects, including 139,392 Aedes mosquitoes and 3,572 other biting flies, nor from 44,785 Aedes mosquitoes reared from larvae and 3,328 ticks collected as nymphs or adults. However, 2 isolates of Cache Valley virus were obtained from Aedes mosquitoes. Serological evidence indicated that JC virus was transmitted to domestic goats during May 1983 and June 1984. Also, antibody was demonstrated in sera obtained from the Eastern Cottontail (4/13), Virginia Opossum (4/25), Raccoon (11/141), and White-tailed Deer (34/47). The absence of JC virus in Aedes mosquitoes in the presence of virus transmission to mammals strongly implies that this virus was maintained and transmitted in this area by arthropods other than Aedes mosquitoes.