Armadillos and leprosy are linked because nine-banded armadillos, a species found in the southern United States, are also vulnerable to the same strain of Mycobacterium leprae that causes leprosy in human beings. Leprosy is rare in the United States (US), affecting no more than a few hundred people yearly. Most of these people are believed to have contracted the disease while traveling in foreign countries where leprosy occurs more frequently, although a smaller number of American leprosy victims contract the disease without ever venturing across US borders. Leprosy is considered a relatively difficult disease to contract, such that the link between armadillos and leprosy is not generally considered a sign that armadillos could threaten human health on a wide scale. Only about one-fifth of armadillos in the United States are infected with leprosy, and humans must typically eat or handle the creatures at length to contract leprosy from them.
People usually contract leprosy only after prolonged exposure to a leprosy patient. Many people, however, have contracted the disease without being exposed to another person who has it. The discovery of a connection between armadillos and leprosy can explain how people who have not experienced prolonged contact with a leprosy patient can contract the disease.
Research has shown that a small number of American leprosy patients had physical contact with armadillos. The connection between armadillos and leprosy was confirmed with DNA testing of bacterial samples. Samples from leprosy patients were compared to samples from armadillos in the area, and it was found that some of these armadillos were infected with the same type of leprosy bacteria that infected the patients.
The verification of a connection between armadillos and leprosy could mean that other types of animals are capable of carrying or suffering from this bacterial disease. Some physicians believe that this could explain the prevalence of leprosy in other countries, where different types of animals may be responsible for the spread of the disease.
Leprosy is a bacterial disease that can cause lesions of the skin and damage to the nerves. Extreme muscle weakness can occur eventually, if the disease is left untreated. The disease is generally easy to treat with antibiotics and is not considered to pose a widespread threat. Leprosy is an ancient disease, and scientists believe that modern humans have become largely resistant to it.