Enzootic mosquito vector species at equine encephalitis transmission foci in the República de Panamá.
Authors: Torres Rolando, Samudio Rafael, Carrera Jean-Paul, Young Josue, Márquez Ricardo, Hurtado Lisbeth, Weaver Scott, Chaves Luis Fernando, Tesh Robert, Cáceres Lorenzo
Journal: PloS one
Summary
# Editorial Summary Equine encephalitis viruses persist in natural transmission cycles across Central America, yet understanding which mosquito species maintain these enzootic foci remains critical for developing targeted vector control strategies in endemic regions. Researchers surveyed three endemic areas in Panama across dry and rainy seasons using three trap types (CDC light traps with octanol, EV traps with CO2, and live hamster-baited Trinidad 17 traps) deployed around the peridomicile and extradomicile of houses over 216 nights, collecting and identifying 4,868 mosquitoes across 45 species and 11 genera. Although Culex (Melanoconion) pedroi—traditionally considered a major Venezuelan equine encephalitis vector—comprised less than 2% of collections, the study documented 14 additional species with demonstrated vector competence for arboviruses, including several Culex Melanoconion subgenus members, Aedes species, Coquillettidia venezuelensis, and Psorophora ferox. The high abundance and diversity of competent vectors identified at these locations suggests the ecological conditions exist to support enzootic transmission cycles of both Venezuelan and Eastern equine encephalitis, indicating that vector control efforts must account for this complex community of potential vectors rather than targeting single species. For equine practitioners in endemic regions, these findings underscore the importance of year-round integrated pest management strategies and vigilant surveillance, as multiple mosquito species with overlapping habitats and seasonal patterns collectively maintain transmission risk.
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Practical Takeaways
- •Equine operations in endemic Panama regions should implement aggressive mosquito control strategies year-round, as high vector species diversity creates significant arboviral transmission risk
- •Vaccination against Venezuelan and Eastern equine encephalitis should be considered essential biosecurity for equines in these geographic areas given confirmed presence of multiple competent vector species
- •Peridomicile and extradomicile mosquito management (removal of standing water, strategic trap deployment) can help reduce vector populations during both dry and rainy seasons
Key Findings
- •4,868 mosquitoes from 45 species and 11 genera were collected across 216 sampling nights in endemic regions of Panama
- •Culex (Melanoconion) pedroi, a major Venezuelan equine encephalitis vector, was relatively rare (<2.0% of samples)
- •14 vectorially competent mosquito species were identified at sampling locations, including multiple Culex Melanoconion species and Aedes species
- •Mosquito abundance and diversity at sampled locations exceeded that typically found in temperate areas, supporting potential for enzootic equine encephalitis outbreaks