Cutaneous leishmaniasis (CL) is a parasitic vector-borne disease present in 98 countries. CL is endemic in Northern Guatemala, affecting the poorest population in rural areas. According to the reports of the World Health Organization, in the last 10 years there has been a rising incidence of CL in Guatemala from 28.9 cases/100,000 inhabitants in 2012 to 33.9 cases/100,000 in 2021. Despite the endemicity of the disease, the most important factors that contribute to the transmission of CL are unknown in the country. Our goal was to update vector knowledge by characterizing the sand fly populations and Leishmania parasites circulating in Alta Verapaz, a CL endemic region in Guatemala. From March to August 2022, we collected sand flies using light traps in three environments: indoors, outdoors in the animal sheds and in the surrounding forest. The sand fly species were identified using end point PCR targeting the cytochrome C gene followed by Sanger sequencing and screened for Leishmania DNA by heat-shock protein 70 gene PCR and sequencing. Using the same methodology on lesion tissue smear material, we identified the species of parasites causing infections in the community. We collected 95 sand flies (79% females) of 10 species, three of which have been previously associated with Leishmania transmission: Nysommyia ylephiletor, Bichromomyia olmeca and Lutzomyia cruciata. The highly anthropophilic Ny. ylpehiletor was the most common species (30%) and was primarily collected indoors (73.1%). Three female sand flies were positive for Leishmania DNA, and one of them (Ny. ylephiletor) was captured indoors. L. guyanensis parasites were found in both sand flies and patients. In patients we also detected L. panamensis and L. braziliensis. The average age of the patients was 34 years old, the majority adults (78%) and men (57%), and 40% of the CL lesions were in the lower legs. This is the first report in Guatemala of the presence of L. guyanensis and L. panamensis in patients and sand flies, and the first characterization of Leishmania infections in humans and sand flies that concur in time and geographical area. The capture of highly anthropophilic sand flies indoors, some with Leishmania DNA, suggest indoor transmission of CL, but further studies are needed to confirm our results. These findings are key to local health authorities for decision-making on the appropriate prevention measures, such as the use of insecticide treated bed nets.
