Under-the-radar dengue virus infections in natural populations of aedes aegypti mosquitoes

Authors: BOYLES, SEAN - University Of Florida; MAVIAN, CARLA - University Of Florida; FINOL, ESTEBAN - Eth Zurich; UKHANOVA, MARIA - University Of Florida; STEPHENSON, CAROLINE - University Of Florida; HAMERLINCK, GABRIELA - University Of Florida; KANG, SEOKYOUNG - University Of Florida; BAUMGARTNER, CALEB - Manatee County Florida; GEESEY, MARY - Manatee County Florida; Rivers, Adam

Submitted to: mSphere
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/12/2020
Publication Date: 4/29/2020
Citation: Boyles, S., Mavian, C., Finol, E., Ukhanova, M., Stephenson, C., Hamerlinck, G., Kang, S., Baumgartner, C., Geesey, M., Rivers, A.R. 2020. Under-the-radar dengue virus infections in natural populations of aedes aegypti mosquitoes. mSphere. 5(2):e00316-20. https://doi.org/10.1128/mSphere.00316-20.
DOI: https://doi.org/10.1128/mSphere.00316-20

Interpretive Summary: Dengue virus has been detected intermittently in Florida over the last decade, primarily from international travelers returning to Florida. In the course of research into the microbes that live in disease-vector mosquitoes, we discovered Dengue Virus 4 (DENV4)in a natural population of mosquitoes from Manatee County, Florida in 2016 and to a lesser extent in 2017. This happened in the absence of any reported human cases of Dengue virus in Florida. The complete genome of DENV4 was constructed and used to understand its divergence from other strains and what may have allowed it to persist in Florida. This finding has implications for the surveillance of mosquito borne diseases.

Technical Abstract: Between 2009-2018 reports of locally acquired dengue infection increased in the United States. This compelled a dramatic increase in research on the flavivirus mosquito vector, Aedes aegypti, and its microbiome, which has been postulated to impact virus transmission success. We examined the microbiomes from four populations of Ae. aegypti mosquitoes collected in 2016-2017 from Manatee County in Southwest Florida. Unexpectedly, we discovered that dengue virus serotype 4 (DENV4) was circulating in these Ae. aegypti populations alongside a host of insect-specific viruses. We assembled the full DENV4 genome, validated infection orthogonally, traced the origin of the virus, and explored the viral genetic signatures and mosquito virome associations that potentially mediated DENV4 persistence in mosquitoes. We discuss the significance of the presence of cryptic dengue infections in Floridian Ae. aegypti that occurred in the absence of any human index cases in 2016 and 2017.