Descriptive and molecular epidemiology of leishmaniasis diagnosed from clinical samples in the United States, 2021-2022

Abstract

Leishmaniasis is a disfiguring, neglected parasitic infection endemic to the Southern United States and the Americas. Despite significant populations at risk—travelers, military and foreign service members, and migrating persons—the epidemiology of the disease in the United States is poorly understood. Moreover, few clinical laboratories in the United States can test for the disease. Here, we present results from 1 year of testing for this disease at a major reference laboratory. These findings are particularly relevant because they coincide with a temporary “pause” on all clinical testing at the CDC. Our findings suggest at least several hundred cases occur each year in the United States. In particular, mucosal leishmaniasis may be more common than previously reported. We also highlight greater genetic diversity in Leishmania species endemic to the Americas than has been previously sampled, with implications for diagnostic specificity.