Origin of a High-Latitude Population of Aedes aegypti in Washington, DC

An overwintering population of Aedes aegypti has been documented in the Capitol Hill neighborhood of
Washington, DC, since 2011. Mitochondrial cytochrome oxidase I (mtCOI) sequence data presented in a previous
study traced the origin to the New World. Here, we use microsatellite and SNP chip data along with more
mitochondrial DNA (mtDNA) sequences on Washington Ae. aegypti samples and samples from potential sources to
further narrow the origin of this population. Genetically, Washington Ae. aegypti are closest to populations in
Florida, meaning this is the most likely source. Florida experienced the first mosquito-borne transmission of dengue
in the United States after decades of absence of this disease, as well as local transmission of chikungunya and Zika
in recent years. This indicates that the Capitol Hill, Washington, DC population of Ae. aegypti is capable of
transmitting viruses such as dengue, chikungunya, and Zika in modern US city environments.