Abundance of three mosquito vectors in Okinawa with relevance to disease risk.

The abundances of three mosquito vectors on Okinawa were determined using New Jersey light traps and compared with data from an identical survey in 1969. The focal distribution of the primary vector of Japanese encephalitis (JE), Culex tritaeniorhynchus Giles, indicates that exposure risks are not uniform throughout the island. The populations of the primary vectors of JE and malaria appear to be declining, resulting in significant changes in the relative abundances of mosquito species. These changes have implications for the current dependent JE immunization program as well as for the possible reintroduction of malaria to Okinawa.