Cohort study of human infection by Leishmania (L.) infantum chagasi in southern Honduras, Central America.

BACKGROUND

In Honduras, Central America, human infection with Leishmania (L.) infantum chagasi can lead to the clinical manifestation known as non-ulcerated cutaneous leishmaniasis (NUCL) and visceral leishmaniasis. This study evaluates the dynamics of human infection with L. (L.) infantum chagasi, focusing on the NUCL form, atypical and rare clinical form of disease.

METHODS

A cohort of 576 individuals from Amapala, southern Honduras, was followed for 2 y with clinical, parasitological and immunological tests: ELISA-IgG/IgM and delayed-type hypersensitivity (DTH) tests were conducted at 12 and 24 mo.

RESULTS

The prevalence was 82% asymptomatic and 18% symptomatic, with only NUCL cases. Among asymptomatic individuals, 44.9% with an indeterminate profile (DTH-/ELISA+) evolved to a final asymptomatic infection profile (DTH+/ELISA-). Among symptomatic individuals, 43% had an early symptomatic profile (DTH-/ELISA-) and evolved to a final symptomatic infection profile (DTH+/ELISA-). Notably, none of the NUCL cases developed visceral disease during the study.

CONCLUSIONS

The results suggest that L. (L.) infantum chagasi infection in southern Honduras is generally benign, as most infected individuals evolved to DTH+ and none of them developed visceral disease.