# Genotype-Specific Vector Competence of Aedes albopictus for Japanese Encephalitis Virus Genotypes I, III, and V

## TL;DR

This study shows that Aedes albopictus mosquitoes can transmit certain types of Japanese encephalitis virus more effectively than others.

## Contribution

The study reveals genotype-specific vector competence of Ae. albopictus for JEV genotypes I, III, and V.

## Key findings

- Ae. albopictus showed high competence for JEV genotype V with 100% dissemination rate and 71.7% head–thorax positivity.
- Genotype III had moderate competence with 76.9% dissemination rate but low transmission rate at 6.6%.
- Genotype I showed minimal infection and negligible transmission potential in Ae. albopictus.

## Abstract

Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, poses a significant public health threat in Asia. Although Culex species are primary vectors, the role of Aedes albopictus in JEV transmission has gained attention under changing ecological conditions. This study evaluated the vector competence of Ae. albopictus for three JEV genotypes: I (GI), III (GIII), and V (GV). Laboratory-reared Ae. albopictus were orally challenged with each genotype, and infection rate (IR), dissemination rate (DR), head–thorax positivity rate (HTR, proxy for potential transmission), and transmission rate (defined as saliva positivity) were assessed at 7 and 14 days post-infection (dpi). Ae. albopictus showed marked genotype-specific differences. By 14 dpi, GV had the highest DR (100.0%) and HTR (71.7%), with viral RNA detected in 36.7% of TR. GIII showed moderate competence (76.9% DR, 39.3% HTR), but low TR (6.6%). In contrast, GI-infected mosquitoes exhibited minimal infection and negligible transmission, with viral RNA rarely detected beyond the midgut. These findings indicate that Ae. albopictus is highly competent for transmitting JEV genotype V and moderately for genotype III, but not genotype I, under laboratory conditions. This highlights its potential role in the transmission dynamics of emerging JEV genotypes and underscores the need for continued surveillance.