1986 Volume 48 Issue 6 Pages 1191-1197
Adult female mosquitoes were collected biweekly over the period from May 11 to October 18, 1980 at two horse habitations in the western areas of Japan. A total of 13 virus strains was isolated in Vero and HmLu-1 cell cultures from 33, 604 mosquitoes. Of the 13 isolates, four were identified as Getah virus and the remaining 9 strains as Japanese encephalitis virus. Of the four virus isolates, three were recovered from 19, 465 mosquitoes of Culex tritaeniorhynchus in 200 pools, the field infection rate being 1:6, 488 at the Miyazaki Race Course (R. C.). Besides, one strain of Getah virus was recovered from 5, 897 mosquitoes of C. tritaeniorhynchus at the Ritto training Center (T. C.). In these studies, C. tritaeniorhynchus was collected predominantly with 85.1% and 54.5% at the Miyazaki R. C. and the Ritto T. C., respectively. On the other hand, Aedes vexans nipponii was captured in an extremely low proportion (less than 2%) from both collection sites. These results suggest that C. tritaeniorhynchus, which is occasionally infected with Getah virus, may act as a main vector of sporadic occurrence of equine Getah virus infection and A. vexans nipponii is a less important vector mosquito in the western areas of Japan.
