Bunyamwera Virus Infection of -Carrying Mosquitoes Reduces Density.

symbionts introduced into mosquitoes provide a highly effective dengue virus transmission control strategy, increasingly utilised in many countries in an attempt to reduce disease burden. Whilst highly effective against dengue and other positive-sense RNA viruses, it remains unclear how effective is against negative-sense RNA viruses. Therefore, the effect of on Bunyamwera virus (BUNV) infection in was investigated using Mel and AlbB, two strains currently used in releases for dengue control, as well as Au, a strain that typically persists at a high density and is an extremely efficient blocker of positive-sense viruses. was found to reduce BUNV infection in vitro but not in vivo. Instead, BUNV caused significant impacts on density of all three strains following infection of mosquitoes. The ability of to successfully persist within the mosquito and block virus transmission is partially dependent on its intracellular density. However, reduction in density was not observed in offspring of infected mothers. This could be due in part to a lack of transovarial transmission of BUNV observed. The results highlight the importance of understanding the complex interactions between multiple arboviruses, mosquitoes and in natural environments, the impact this can have on maintaining protection against diseases, and the necessity for monitoring prevalence at release sites.