Last Updated on December 13, 2024
Aedes albopictus Skuse, Culex pipiens form molestus, Culex quinquefasciatus Say, and Culex tritaeniorhynchus Giles mosquitoes from nonendemic JEV regions may be able to efficiently transmit JEV genotype IV in nature. This is the conclusion of an article published on December 10, 2024 in Emerging Microbes & Infections.
Researchers exposed these mosquito species in a laboratory to a JEV genotype IV blood meal that contained virus strain 19CxBA-83-Cv that was collected from domestic pigs on southern Bali Island, Indonesia in 2019. This JEV genotype IV strain has a ≈ 99% nucleotide similarity to a JEV genotype IV strain collected from pigs on Bali Island in 2017 (reference JEVISN / Epidemiology / Spread of JEV genotype IV for additional information).
Colonies of JEV genotype IV infected mosquito species showed the following 14-day post-exposure salivary transmission efficiency rates:
| Mosquito Species | Origin of Mosquito Colony | Transmission Efficiency Rate |
| Culex tritaeniorhynchus Giles | Japan | ≈ 74% |
| Aedes albopictus Skuse | Japan | ≈ 52% |
| Culex quinguefasciatus Say | Vietnam | ≈ 35% |
| Culex pipiens form molestus | Turkey | ≈ 18% |
Although researchers measured JEV genotype IV viral loads from collected abdomens and thoraxes (as a measure of infection) and collected heads, wings, and legs (as a measure of dissemination), the presence of JEV genotype IV in saliva demonstrated an ability to transmit the virus when feeding.
Results from this study suggest that increased surveillance for JEV genotype IV in these and other mosquito species in global nonendemic JEV regions should be considered.
In JEV endemic regions, Culex pipiens, Culex quinquefasciatus, and Culex tritaeniorhynchus are highly competent JEV vectors, and Aedes albopictus is a confirmed JEV vector (reference JEVISN / Ecology / Mosquito Vectors for additional information).