With some genetic sleuthing, scientists have identified a likely culprit in the spread of leprosy in the southern United States: the armadillo.
DNA tests show a match in the leprosy strain found in some patients and in the animals. "Now we have the link," said James Krahenbuhl, who heads the government leprosy programme that led the new study. To develop the disease requires frequent handling of armadillos or eating their meat.
Only about 150 leprosy cases occur each year in the US, mostly among travellers to places such as India, Brazil and Angola, where it's more common. But the nine-banded armadillo is one of the few indigenous mammals that harbour the bacteria that cause the often-disfiguring disease, which first shows up as an unusual lumpy skin lesion.
Researchers at the National Hansen's Disease Programmes in Baton Rouge, Louisiana, led an international team of scientists who published their findings in yesterday's New England Journal of Medicine.
DNA samples were taken from 33 wild armadillos in Arkansas, Alabama, Louisiana, Mississippi and Texas. Scientists also took skin biopsies from 50 leprosy patients being treated at a Baton Rouge clinic. Three-quarters had never had foreign exposure, but lived in southern states where they could have been exposed to armadillos.