Transmission of Japanese Mosquitoes Against West Nile Virus

Transmission of Japanese Mosquitoes Against West Nile Virus 

Intrathoracically inoculated Cx. p. pallens mosquitoes were prepared for the WNV transmission experiment. They seemed to be infected theoretically with approximately 100% WNV. Anesthetized BALB/c mouse was given as feed blood for the mosquitoes 14-day post infection. Some mice were recognized with symptoms 3 to 10 days post-infection. In one of three mice, West Nile viral genome was detected in mouse blood. Similar positive data was obtained on Cx. inatomii, 

Culex p. pallens, Cx. p. molestus, and Cx. quinquefasciatus may become epi-demiologically important, if WNV is introduced in Japan. Five mosquito species, Cx. p. pallens, Cx. p. molestus, Cx. inatomii, Ae. albopictus, and Och. japonicus, were discriminated as possible vectors of WNV. 

A reduction of the vector population through elimination of larval breeding sites and use of larvicides may be one of keys for the prevention of dengue fever and West Nile fever outbreaks. An increase in the number of WNV-infected patients on the west coast of the USA caused the first domestically imported case in Japan in 2005. Establishment of national countermeasures, such as strengthening of quarantine organizations and vector surveillance around the international air and seaports, is needed in the absence of an effective vaccine. Extensive source-reduction countermeasures of mosquito larvae by local government and individuals must be developed at a community level. 

Kurane, in Anthology VI Arthropod Borne Diseases, J. Y. Richmond (Ed.), American Biological Safety Association, Illinois, 2003, 63-71. 

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