Epidemiological and Molecular Surveillance of Leishmania Species among Humans, Vectors, and Dogs in a Wildland-Urban Interface of Cartagena, Colombia.

In Colombia, human leishmaniasis is endemic in rural areas, with increasing reports of outbreaks and cases in urban areas. Cartagena, an urban city in the Colombian Caribbean with a wildland-urban interface, faced its first local cases between 2011 and 2015. Despite reports, visceral leishmaniasis (VL) remains neglected and understudied and almost devoid of active surveillance. Here we report the epidemiological and molecular surveillance of Leishmania species in humans, domestic dogs, and sandflies at the wildland interface in two poverty-stricken neighborhoods of Cartagena. In October 2021, we conducted a surveillance study in the El Toril and La Quinta neighborhoods. Blood samples were collected from 150 healthy humans and 77 domestic dogs for Leishmania species testing by using molecular tools. Five human samples (3.3%) tested positive for Leishmania, one case in El Toril and four cases in La Quinta. The Leishmania donovani complex was detected in three human samples, and all dog samples tested negative for Leishmania. CDC light traps placed for three consecutive days in peridomiciliary areas of the Leishmania-positive case in El Toril allowed the capture of seven females of Lutzomyia dubitans, but none tested positive for Leishmania. Multiple attempts to conduct entomological surveillance in La Quinta were unsuccessful because of non-study-related issues. Our findings contribute to the characterization of the epidemiology of VL in Cartagena, revealing possible neglected cryptic infections in two neighborhoods with an urban-wildland interface.