DNA tests link Southern leprosy cases to armadillo

Updated: Apr 28, 2011, 00:00 AM IST

Los Angeles: With some genetic sleuthing, scientists have fingered a likely culprit in the spread of leprosy in the southern United States: the nine-banded armadillo.

DNA tests show a match in the leprosy strain between some patients and these prehistoric-looking critters a connection scientists had suspected but until now couldn`t pin down.

"Now we have the link," said James Krahenbuhl, who heads a government leprosy program that led the new study.

Only about 150 leprosy cases occur each year in the US, mostly among travellers to places like India, Brazil and Angola where it`s more common.
The risk of getting leprosy from an armadillo is low because m

ost people who get exposed don`t get sick with the ancient scourge, known medically as Hansen`s disease and now easily treatable.

Armadillos are one of the very few mammals that harbour the bacteria that cause the sometimes disfiguring disease, which first shows up as an unusual lumpy skin lesion.

Researchers at the National Hansen`s Disease Programsin Baton Rouge, Louisiana, led an international team of scientists who published their findings in Thursday`s New
England Journal of Medicine. They think it requires frequent handling of armadillos or eating their meat for leprosy to spread.

DNA samples were taken from 33 wild armadillos in Arkansas, Alabama, Louisiana, Mississippi and Texas, where they`re sometimes referred to as "hillbilly speed bumps"
because they`re often run over by cars.

Scientists also took skin biopsies from 50 leprosypatients 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.

An analysis found that samples from the patients and armadillos were genetically similar to each other and were different from leprosy strains found elsewhere in the world.
The unique strain was found in 28 armadillos and 25 patients.

Of the 15 patients for whom researchers had information, seven said they had no contact with armadillos; eight said they did, including one who routinely hunted and
ate them.

While the work did not document direct transmission from animal to human, "the evidence is pretty convincing that it happens," said Dr. Brian Currie, an infectious disease
expert at Montefiore Medical Center in New York, who had no role in the study.

Bureau Report