Comparative vector competence analysis reveals differential Tembusu virus transmission efficiency between Aedes...

The Tembusu virus (TMUV) is a mosquito-borne pathogen affecting the birds, causing economic losses in poultry and potential public health risks. Research mainly focuses on virus's characteristics and its interaction with birds, especially the ducks, while entomological studies monitor mosquito populations for epidemiological insights. TMUV's transmission dynamics are not fully understood, with varying abilities of mosquito species to transmit the virus. There is limited research on the vector competence and vertical transmission potential of different mosquito species, particularly in China. We compared the vector competence of Culex quinquefasciatus and Aedes albopictus for TMUV.

The vector competence of Culex quinquefasciatus and Aedes albopictus for TMUV was assessed through intrathoracic microinjection and artificial membrane feeding techniques. Mosquitoes were sampled at 1-, 3-, 6-, and 9-days post-inoculation (dpi) following intrathoracic microinjection of TMUV, and at 4-, 8-, and 14-dpi following artificial membrane feeding. Samples of heads, midguts, and salivary glands were collected for subsequent analysis. Furthermore, the potential for vertical transmission of TMUV over two gonotrophic cycles was evaluated using the artificial membrane feeding approach. The distribution of TMUV within various organs and tissues of both mosquito species at 4-, 8-, and 14-dpi was investigated by immunofluorescence assays.

The findings suggest that both Culex quinquefasciatus and Aedes albopictus are effective carriers of TMUV, with Aedes albopictus showing greater vector competence. Vertical transmission of TMUV was observed in both species across two successive oviposition cycles, with Aedes albopictus displaying slightly higher efficiency.

This study represents the inaugural comparative assessment of vector competence between Sichuan-native Culex quinquefasciatus and Aedes albopictus (Guangzhou) for TMUV, thereby addressing critical research gaps and providing novel insights for the development of TMUV biocontrol strategies.