P-42 - Distribution of Anopheles Mosquitoes in the USA to Support Locally Acquired Malaria Outbreak Response

Human malaria is a life-threatening parasitic disease transmitted by the bite of an Anopheles mosquito. Though it was formerly endemic in the USA, malaria was considered eliminated by the early 1950s. Nevertheless, multiple native Anopheles species persist across much of the USA and could transmit malaria in the event of a re-introduction. Cases of malaria acquired in the USA without a history of travel to a malaria-endemic country are rare. However, in 2023, ten locally acquitted malaria cases were detected in the USA – the first in 20 year – highlighting a lack of current awareness around the distribution of Anopheles species in the USA. Prevention of local malaria transmission requires reducing contact between parasitemic people and vectors, along with vector surveillance and control. Thus, up-to-date knowledge about the distribution of malaria vectors in the USA is critical. We therefore created an Anopheles distribution mapping application in R Shiny. To populate the map, an exhaustive literature review was conducted. All sources reporting Anopheles in the continental USA, together with Alaska and Puerto Rico, from 1980 and after were reviewed and included when appropriate. Data from the early 2000s and later were also obtained (with permission) and compiled from public health partners in state and jurisdictional mosquito control. The application presents 19 options of Anopheles species to map and reports presence-only at the county level. It is currently an internal CDC weblink (though it will hopefully become public), through which users can select a species and view descriptions at the county level of the data source(s) and their respective collection year(s). This mapping application and its continuous updating will add to the limited knowledge of Anopheles distribution in the USA, provide valuable vector data for locally acquired malaria mitigation efforts, and contribute to predictive malaria risk modeling and mapping efforts for the USA.