Can domestic dogs be considered a good reservoir of Leishmania (L.) infantum chagasi in an endemic area of nonulcerated cutaneous leishmaniasis in Southern Honduras?

This study was supported by the FAPESP, grant Nº 2014/50315-0; CNPq grant Nº 308817/2021-4; DICIHTUNAH grant Nº PI-195-DICIHT; DSEP-UNAH and LIM50 HC-FMUSPUniversidad Nacional Autónoma de Honduras. Instituto de Investigaciones en Microbiologia. Tegucigalpa, Honduras / Universidad Nacional Autónoma de Honduras. Posgrado en Salud Pública. Tegucigalpa, Honduras.Universidad Nacional Autónoma de Honduras. Instituto de Investigaciones en Microbiologia. Tegucigalpa, Honduras.Universidade de São Paulo. Faculdade de Medicina. Hospital das Clínicas. Laboratório de Investigação Médica. São Paulo, SP, Brazil.Universidad Nacional Autónoma de Honduras. Posgrado en Salud Pública. Tegucigalpa, Honduras.Universidad Nacional Autónoma de Honduras. Instituto de Investigaciones en Microbiologia. Tegucigalpa, HondurasUniversidad Nacional Autónoma de Honduras. Instituto de Investigaciones en Microbiologia. Tegucigalpa, HondurasUniversidade de São Paulo. Faculdade de Medicina. Laboratório de Patologia de Moléstias Infecciosas. São Paulo, SP, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde e Ambiente. Instituto Evandro Chagas. Laboratório de Leishmanioses. Ananindeua, PA, Brasil / Universidade Federal do Pará. Núcleo de Medicina Tropical. Belém, PA, Brazil.Universidad Nacional Autónoma de Honduras. Instituto de Investigaciones en Microbiologia. Tegucigalpa, Honduras.Universidade de São Paulo. Faculdade de Medicina. Laboratório de Patologia de Moléstias Infecciosas. São Paulo, SP, Brazil.Universidade de São Paulo. Faculdade de Medicina. Laboratório de Patologia de Moléstias Infecciosas. São Paulo, SP, Brazil.Dogs are considered to be the main domestic reservoir associated with the transmission of Leishmania (L.) infantum chagasi to humans in endemic areas of visceral leishmaniasis in America. However, little is known about the role of canines as a source of infection in endemic areas of nonulcerated cutaneous leishmaniasis (NUCL). Therefore, the objective of the present study was to investigate the role of dogs as a possible reservoir of the parasite in Southern Honduras. Dogs (n = 107) living with individuals affected by NUCL were clinically examined and biological material was collected for parasitological and immunological diagnosis. Most animals showed a healthy appearance and a few presented slight weight loss (64%), alopecia (7%), onychogryphosis (5%) and skin lesions (1%). The overall seroprevalence of Leishmania infection based on the DDP® quick test and/or in-house ELISA serological test was 41%. The presence of the parasite’s DNA was confirmed in 94% of the dogs; however, the average parasite load in the buffy coat was low at 6.09 parasites/µL, ranging between 0.221 and 50.2. The skin of seropositive dogs examined by histopathology using paraffin sections stained by hematoxylin and immunohistochemistry did not show cutaneous lesions or parasite amastigotes. Based on the absence of parasites in the skin and the low parasite load detected in the buffy coat, it seems that the dog does not represent a good source of infection for the vector in the endemic area of NUCL transmission in Southern Honduras. Other domestic and/or wild animals should be investigated