Armadillo exposure and Hansen's disease: An epidemiologic survey in southern Texas

Background: Naturally occurring leprosy has been demonstrated in wild nine-banded armadillos (Dasypus novemcinctus). This suggests a possible mode of transmission of human leprosy in regions where armadillo contact is prevalent. Objective: Our purpose was to study the possible relationship between armadillo exposure and Hansen's disease. Method: One hundred one patients (67 men, 34 women) with established Hansen's disease seen in the Hansen's Disease Clinic in Houston, Texas, were questioned about their exposure to armadillos. These patients were divided into two groups: Asian (n = 32) and non-Asian (n = 69). Results: Seventy-one percent of the non-Asian patients surveyed reported either direct or indirect armadillo exposure. None of the Asian patients reported armadillo exposure (P < .001). Of the non-Asian patients, 75.4% had lepromatous disease versus 50.0% of the Asian patients (P < .001). The average age at diagnosis for the non-Asian group with Hansen's disease in this study was 51 versus 38 years for the Asian group (P < .001). Conclusion: Although it is yet to be determined whether direct transmission from the armadillo to human occurs, it is likely based on the high incidence of armadillo exposure in non-Asian patients with Hansen's disease in our study population that this animal acts as a reservoir for human disease. However, the Asian patients reporting no known armadillo exposure likely obtained the disease from person-to-person contact in their respective countries of origin where Hansen's disease has a much higher prevalence.