Armadillos are the most likely cause of unexplained cases ofleprosy among people with the disease in the southern U.S., where the animals are hunted and eaten, a study found.
Using genomic analysis, researchers identified the same strain of leprosy in 28 of 33 wild armadillos and 25 of 39 patients who lived in states where the animals are common, according to the study published today in the New England Journal of Medicine. Exposure to fresh armadillo blood or tissue raises the risk of leprosy infection, researchers said.
In the U.S., only about 150 new cases of leprosy, also known as Hansen’s disease, are reported each year, the majority of which occur in people who lived or worked in places outside the country where the disease is more prevalent, the study said. About one third of U.S. cases aren’t linked to a cause, and the study helps doctors understand how many of those infections occur, researchers said.
“It’s extremely likely that the people who have never been exposed to a human who has leprosy, it’s very likely they got leprosy from exposure to an armadillo,” said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, in an April 26 telephone interview.
Leprosy, an infectious disease known since biblical times, causes disfiguring sores and nerve damage and is found mostly in tropical and semitropical regions of the world. The illness, caused by Mycobacterium leprae, is curableusing antibiotics.
People who hunt armadillos or prepare them for food have a small risk of catching the disease from the animals, said lead study author Richard Truman, chief of microbiology at the National Hansen’s Disease Program, part of the U.S. Department of Health and Human Services, in Baton Rouge, Louisiana. Only a small percentage of armadillos are actually infected with leprosy, he said.
“Susceptibility to leprosy itself is relatively rare. Probably 95 percent of the world’s population is naturally immune to this infection,” said Truman, in an April 26 telephone interview.
Among the 50 people examined, 39 lived in areas where they could have been exposed to leprosy from armadillos and of those 39, 29 never lived outside the U.S. The researchers found that 25 of the 39, including 22 of the 29, carried the strain of the leprosy bacterium found in 28 of the 33 wild armadillos.
“There are very few cases in this country, so this does not have broad public health implications,” Fauci said.
Still, he said, those who do come into contact with armadillos either through hunting or preparing the animals to be eaten should be aware that they can contract the disease.
Today’s study was sponsored in part by the National Institutes of Health.
Using genomic analysis, researchers identified the same strain of leprosy in 28 of 33 wild armadillos and 25 of 39 patients who lived in states where the animals are common, according to the study published today in the New England Journal of Medicine. Exposure to fresh armadillo blood or tissue raises the risk of leprosy infection, researchers said.
In the U.S., only about 150 new cases of leprosy, also known as Hansen’s disease, are reported each year, the majority of which occur in people who lived or worked in places outside the country where the disease is more prevalent, the study said. About one third of U.S. cases aren’t linked to a cause, and the study helps doctors understand how many of those infections occur, researchers said.
“It’s extremely likely that the people who have never been exposed to a human who has leprosy, it’s very likely they got leprosy from exposure to an armadillo,” said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, in an April 26 telephone interview.
Leprosy, an infectious disease known since biblical times, causes disfiguring sores and nerve damage and is found mostly in tropical and semitropical regions of the world. The illness, caused by Mycobacterium leprae, is curableusing antibiotics.
Leprosy Carriers
Armadillos, mammals known for their leathery armor, are found in Texas, Louisiana, Mexicoand areas of Central and South America. They are the only nonhuman animals known to harbor the leprosy infection. Since scientists in the 1970s discovered armadillos’ susceptibility to leprosy, the creatures have been the primary animal model in research on the disease, according to background information in the study.People who hunt armadillos or prepare them for food have a small risk of catching the disease from the animals, said lead study author Richard Truman, chief of microbiology at the National Hansen’s Disease Program, part of the U.S. Department of Health and Human Services, in Baton Rouge, Louisiana. Only a small percentage of armadillos are actually infected with leprosy, he said.
Leprosy DNA
The researchers analyzed leprosy DNA in 50 people with the disease and 33 wild armadillos captured in Texas, Louisiana, Mississippi, Arkansasand Alabama to try to determine a common link. Armadillos outside these states haven’t been found to carry leprosy, Truman said.
Among the 50 people examined, 39 lived in areas where they could have been exposed to leprosy from armadillos and of those 39, 29 never lived outside the U.S. The researchers found that 25 of the 39, including 22 of the 29, carried the strain of the leprosy bacterium found in 28 of the 33 wild armadillos.“There are very few cases in this country, so this does not have broad public health implications,” Fauci said.
Still, he said, those who do come into contact with armadillos either through hunting or preparing the animals to be eaten should be aware that they can contract the disease.
Today’s study was sponsored in part by the National Institutes of Health.
