Aside from humans, the armored mammals are among only a handful of other known natural hosts of the disease in the world.
More than 20 percent of armadillos tested in parts of the South have been found infected with the bacterium that causes the treatable disease.
Richard W. Truman, director of microbiology at the National Hansen’s Disease Program in Baton Rouge, used genetic analysis to study the connection.
He and colleagues found that infected humans who had not traveled to areas where leprosy is a serious health problem share the same leprosy bacterium strain as local armadillos.
It’s believed humans contract the disease by handling armadillos or consuming their meat.
The animals are most common in Texas, but they are expanding their range in Florida, and northward into the Midwest.