Leprosy in Missouri, USA: Are Armadillos (Dasypus mexicanus) Carrying the Causative Agent Mycobacterium leprae?

The Mexican long-nosed nine-banded armadillo (Dasypus mexicanus) has continued to expand its range since it was first documented in Texas, US, in the mid-1800s. It dispersed north and east and was found in Missouri, USA, starting in the 1980s. This species is known to contract leprosy, also known as Hansen's disease, caused by Mycobacterium leprae. Infected armadillos are considered to be a zoonotic source of leprosy in the US. A recent case (2021) of leprosy in a native Missourian who had a history of contacts with armadillos appears to have been locally acquired. However, no data were available on the presence or prevalence of leprosy in wild armadillos from Missouri. We sampled various tissues from 64 armadillos, 39 road killed and 25 hunter killed/culled, from southwestern and central Missouri in summer 2022 to determine the local prevalence of M. leprae. Two animals were PCR positive for M. leprae, providing evidence that this pathogen is moving northward along with the range expansion of Mexican long-nosed armadillos.