Flavivirus-mosquito interactions

Abstract

The Flavivirus genus is in the family Flaviviridae and is comprised of more than 70 viruses. These viruses have a broad geographic range, circulating on every continent except Antarctica. Mosquito-borne flaviviruses, such as yellow fever virus, dengue virus serotypes 1-4, Japanese encephalitis virus, and West Nile virus are responsible for significant human morbidity and mortality in affected regions. This review focuses on what is known about flavivirus-mosquito interactions and presents key data collected from the field and laboratory-based molecular and ultrastructural evaluations.

Figure 1

Transmission cycles of yellow fever virus (YFV) in Africa and South America. (A) Three transmission cycles support the transmission of YFV in Africa. In the jungle cycle, Ae. africanus is responsible for the transmission among non-human primates. In the intermediate cycle, human activities result in the biting of intermediate cycle vectors. In the urban transmission cycle, Ae. aegypti transmits YFV by feeding on viremic humans; (B) Two transmission cycles of YFV exist in South America. In the jungle cycle, H. janthinomys and S. chloropterus feed on infected non-human primates. In the urban cycle, Ae. aegypti are responsible for virus transmission.

Figure 2

Transmission of Japanese encephalitis virus (JEV) is mainly maintained between viremic amplification hosts and Culex mosquitoes, especially Cx. tritaeniorhynchus. Infection of incidental hosts, such as humans, are unable to cause high titer viremia and sustain the transmission.