Prevalence and incidence density of Mycobacterium leprae and Trypanosoma cruzi infections within a population of wild nine-banded armadillos

Abstract

A total of 415 wild 9-banded armadillos from the East Atchafalaya River Levee (Point Coupee, LA) were collected over 4 years to estimate the incidence and prevalence of Mycobacterium leprae and Trypanosoma cruzi and to discern any relationship between the 2 agents. M. leprae infections were maintained at a high steady prevalence rate year to year averaging 19%. T. cruzi antibody prevalence remained relatively low, averaging 3.9%, and varied markedly between years. Prevalence rates were independent, with only 3 armadillos coinfected with both agents. M. leprae incidence density ranged from 0.47 to 3.5 cases per 1,000 animal-days, depending on case definition, confirming active intense transmission of M. leprae among armadillos. No incident T. cruzi cases were found. These infections seem to occur independently and may be used in comparisons to understand better factors that may influence transmission of these agents.