About
Japanese encephalitis cases are mostly found in the Asia-Pacific region and this restriction is linked to the geographical distribution of JEV main vector, Culex tritaeniorhynchus. In order to assess the potential for JEV emergence in Europe, we decided to evaluate the vector competence of European mosquitoes species for the circulating JEV genotypes g1, g3 and g5. We compared JEV infection of two mosquitoes species isolated in France, Culex pipiens and Aedes albopictus, to infection of JEV main vector, Culex tritaeniorhynchus, obtained from Japan. The mosquitoes were infected per os and the virus distribution in different organs (midgut, head, legs, salivary glands) was measured at different times post-infection. In addition the transmission capacity of each vector was evaluated by measuring the amount of virus released in saliva. So far, the data obtained after infection with JEV-RP-9 (g3) and JEV-XZ0934 (g5), showed that the European Culex pipiens and Aedes albopictus could readily be infected with those viruses and could transmit them to similar or even higher levels than Culex tritaeniorhynchus. We also evaluated the transmission of JEV-CNS769_Laos_2009, a genotype 1 strain in Culex pipiens. Preliminary data indicate that it is transmitted at a lower level than genotype 3 and 5. In the forthcoming months, we will also evaluate the infection and transmission of JEV-CNS769_Laos_2009 in Aedes albopictus and establish the vector competence of a Parisian population of Culex pipiens isolated in August 2014 as well as European populations of Culex tritaeniorhynchus.
