A longitudinal study of the prevalence of Japanese encephalitis virus in adult and larval Culex tritaeniorhynchus mosquitoes in northern Taiwan.

Adult females and larvae of Culex tritaeniorhynchus were collected year-round for 3 1/2 years at a site near Taipei, Taiwan. One hundred sixty-four isolates of Japanese encephalitis (JE) virus were obtained from approximately 142,000 adult females and 1 isolate of the virus was obtained from approximately 382,000 larvae. Virus was recovered from adult females every year, except the first, beginning in May. The single larval isolate was from specimens collected in June. The vertical transmission of JE virus in Cx. tritaeniorhynchus as a possible inter-epidemic viral survival mechanism is examined.