LOS ANGELES -- They're cute. They're often roadkill. Some gourmets say they're tasty, whether baked or barbecued. Now, Louisiana researchers have learned something else about nine-banded armadillos.
"A preponderance of evidence shows that people get leprosy from these animals," said Richard Truman, director of microbiology at the National Hansen's Disease Program in Baton Rouge and lead author of a paper detailing the discovery in the New England Journal of Medicine.
Until now, scientists believed that leprosy was passed only from human to human. Every year, about 100 to 150 people in the United States are diagnosed with the malady, which is also known as Hansen's disease. Although many have traveled to countries where the disease is relatively common, as many as one-third don't know where they picked it up.
Most of those cases are in Texas and Louisiana, where leprosy-infected armadillos live, too. Now, Mr. Truman said, "we're able to provide a link."
Leprosy is caused by the bacterium Mycobacterium leprae, a cousin of the microbe that causes tuberculosis. People with leprosy develop skin lesions; severe cases can cause nerve damage or disfigurement in the limbs.
Over the years, M. leprae has proved hard to study, its migration around the globe hard to plot, for a variety of reasons. The bacterium can't be grown in a lab dish. Leprosy has a years-long incubation period and propagates slowly. It is hard to contract -- only 5 percent of humans are susceptible, and even they usually need to have close and repeated contact with M. leprae to develop an infection.
In the past, people with leprosy were confined to leper colonies. Today, it is treatable with a combination of three antibiotics, said James Krahenbuhl, director of the National Hansen's Disease Program.
About 3,600 people in the United States have the disease, he added, and they aren't expected to die from it.
For years, scientists had known that other than humans, armadillos are the only known natural hosts for M. leprae in the world. Some armadillos die from the disease, and in some parts of the South, more than 20 percent of armadillos have the infection.
First Published: April 28, 2011, 4:00 a.m.