Volume 43, Issue 4
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645



The persistence of arboviruses was studied from 1983 to 1988 in mixed agriculture, marsh, riparian, and foothill habitats in Kern County, CA. Western equine encephalomyelitis (WEE) virus was isolated frequently during 1983 from and and was detected by the seroconversion of sentinel chickens. WEE virus then disappeared, even though vector competence studies during 1984–1986 showed that was able to transmit WEE virus. St. Louis encephalitis (SLE) virus was detected sporadically in 3 of the 6 years of the study by isolation from and/or by sentinel chicken seroconversion. When mosquito pools were screened for virus in suckling mice, Turlock (TUR) and Hart Park (HP) viruses were isolated from during each summer. Vertical transmission of HP was indicated by the isolation of virus from a pool of male . California encephalitis (CE) virus was isolated repeatedly from host-seeking females, males, and adults reared from field-collected immatures, verifying vertical transmission in nature. Horizontal transmission of CE virus among both jackrabbits () and desert cottontails () appeared to amplify infection rates during the summer of 1985, but elevated herd immunity depressed infection rates during 1986. Thus, CE, HP, and TUR viruses persisted in Kern County, while WEE virus appeared to become extinct and required reintroduction. The sporadic occurrence of SLE virus activity remains unexplained, but its persistence may require both vertical transmission and reintroduction.


Article metrics loading...

The graphs shown below represent data from March 2017
Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error