Dispersion of Nyssomyia whitmani in the endemic rural area of cutaneous leishmaniasis, Iguazú, province of Misiones, Argentina.

We analyzed the dispersal capacity of Nyssomyia whitmani (Antunes & Coutinho 1939), one of the main species involved in the transmission of the etiological agent of Cutaneous Leishmaniasis (CL), in the Paranaense-Atlantic region of Argentina. The transmission of CL is influenced by ecological, climatic and social factors, and phlebotomine sand flies populations are affected by habitat modifications, such as deforestation, which favors contact between humans and vectors. The study focused on determining the dispersal distance of Ny. whitmani through mark-release-recapture experiments, in which adult sandflies were captured, marked with fluorescent powders, and released either at the same capture site or at predefined nearby sites on the same night of capture. Over 66,000 phlebotomine specimens were captured, of which 14,920 were used in the experiment. Recaptures indicated that females of Ny. whitmani were recaptured more frequently and at greater distances than males, suggesting a tendency to disperse from release sites to nearby areas with food sources, such as animal pens. The results support the hypothesis of a sylvatic-peridomestic transmission cycle, with a focal distribution of vector populations, especially in areas near vegetation and blood sources. These findings are key to designing control strategies, such as physical barriers between humans and phlebotomine sand flies, and improving preventive measures in CL endemic areas.