Encephalitis on Taiwan

Abstract

SummaryOver 100,000 Culex tritaeniorhynchus and over 150,000 Culex fuscocephalus mosquitoes caught on Taiwan throughout the year were tested for virus by inoculation into infant mouse brain. Virus was isolated from 22 pools of the former and 1 pool of the latter species. No virus was isolated from 9 other species tested. All but one virus isolation came from mosquitoes collected between July 3 and 26, 1958, and June 3 and 26, 1959. All positive C. tritaeniorhynchus pools were collected in northern Taiwan. The one positive C. fuscocephalus pool came from southern Taiwan. All isolated virus strains were shown to belong to the Japanese encephalitis virus group by complement fixation test. Neutralization tests with 6 Taiwan virus strains showed close similarity among the strains and prototype JE virus. It is concluded that C. tritaeniorhynchus is the important vector of JE virus in northern Taiwan.