The good, the BATV, and the ugly - first report of BATV vector competence in Culex quinquefasciatus from the Southern United States

Batai virus is an arbovirus with wide geographic, host, and climactic ranges. BATV infects primarily avian species but can cause disease in ruminants and humans. Louisiana is at particular risk for overlaps in natural and agricultural systems as the Mississippi Flyway passes through the state. We assessed the vector competence of Louisiana Cx. quinquefasciatus for BATV and found infection and dissemination rates of 22% and 11.1% at 7 days post-exposure (dpe), and 15.8% and 5.3% at 21dpe. The current H5N1 avian influenza outbreak in dairy cows demonstrates the importance of understanding the overlap in avian and other vertebrate species to inform public health and agricultural biosecurity. Results indicate a moderate vector competence of regional Louisiana Cx. quinquefasciatus for BATV. This study presents the first known report of vector competence of BATV in US mosquitoes and establishes the non-zero risk of its emergence in the southern US.