Vector Competence of Australian Mosquitoes for Yellow Fever Virus

The vector competence of Australian mosquitoes for yellow fever virus (YFV) was evaluated. Infection and transmission rates in Cairns and Townsville populations of Aedes aegypti and a Brisbane strain of Ae. notoscriptus were not significantly different from a well-characterized YFV-susceptible strain of Ae. aegypti. After exposure to 10(7.2) tissue culture infectious dose (TCID(50))/mL of an African strain of YFV, > 70% of Ae. aegypti and Ae. notoscriptus became infected, and > 50% transmitted the virus. When exposed to 10(6.7) TCID(50)/mL of a South American strain of YFV, the highest infection (64%) and transmission (56%) rates were observed in Ae. notoscriptus. The infection and transmission rates in the Cairns Ae. aegypti were both 24%, and they were 36% and 28%, respectively, for the Townsville population. Because competent vectors are present, the limited number of travelers from endemic areas and strict vaccination requirements will influence whether YFV transmission occurs in Australia.