Malaria, once a deadly disease for Americans, was officially eliminated from the US in 1951. Though the disease was eliminated, the vectors, Anopheles mosquitoes, remain. Most of the malaria cases observed in the US are travel-related cases, but there have been cases of autochthonous malaria transmission in recent years. Outbreaks occurred in Florida, Texas, Arkansas, and Maryland in 2023 and in New Jersey and Washington in 2025. Thus, surveillance of Anopheles within the US remains useful in managing malaria outbreaks.
In this study, Anopheles spp. bycatch data from 2001-2024, resulting from arbovirus vector surveillance, was examined to understand the spatiotemporal trends in Anopheles spp. in Georgia and assess the utility of long-term bycatch data.
There were 47,621 Anopheles spp. trapped as bycatch from arbovirus vector surveillance activities. CDC light traps and gravid traps were consistently used throughout the study period. Light traps captured 85% of the Anopheles spp. collected over the 24-year study period. Based on the total number of Anopheles spp. and sites of collection, temporally consistent bycatch hotspots were found in the metro Atlanta and southeastern regions. Anopheles spp. persisted year-round, with Anopheles crucians consistently being the most abundant species. An. crucians displayed hotspot patterns distinct from An. punctipennis and An. quadrimaculatus, the next greatest species in abundance. The total numbers of mosquitoes of each of these three species peaked in 2019 or early 2020.
This dataset demonstrated the value in using long-term consistently collected bycatch data. Information on the location and composition of malaria vector populations and the best trapping methods is integral in the event of a malaria outbreak, enabling targeted and effective mosquito control response. Thus, it would be beneficial to recognize bycatch data as a key component of vector control, as well as advocate for wider retention and analysis of bycatch.
