Detection of Leishmania infantum DNA in Sand Flies and Assessment of Zoonotic Transmission Risk in Central Honduras: A One Health Approach

Abstract

Integrated One Health studies are essential for assessing the risks of leishmaniasis transmission. In Honduras, the most prevalent clinical presentation of leishmaniasis is the non-ulcerated cutaneous form caused by Leishmania infantum; however, research on its transmission dynamics remains limited. This study aimed to characterize the eco-epidemiology of leishmaniasis and identify potential zoonotic risk factors in the municipality of Ojos de Agua, Department of Comayagua, central Honduras, using a One Health approach. We collected sand flies using CDC light traps placed in intra- and peridomestic settings of households with a history of leishmaniasis. Concurrently, we evaluated domestic dogs and collected blood samples for serological and molecular testing. We also conducted active surveillance among community residents to identify human infections. We collected a total of 644 phlebotomine sand flies, including 186 females. We identified eight sandfly species, with Lutzomyia (Lutzomyia) longipalpis as the predominant species, followed by Pintomyia (Pifanomyia) evansi. Among the 64 engorged females screened, the overall PCR positivity rate for Leishmania spp. was 14.1% (9/64). Blood meal analysis of PCR-positive sand flies identified humans and pigs as blood and meal sources. Additionally, 18.6% (8/43) of domestic dogs were seropositive for Leishmania spp., and 23.3% (10/43) tested positive by PCR. DNA sequencing identified the infecting species as Leishmania infantum. We detected no active human cases during the study period. These findings highlight the value of a One Health approach for improving transmission risk monitoring in newly emerging areas with a history of ulcerative cutaneous leishmaniasis in Honduras.