April 28, 2011

Leprosy in the U.S.?

(Ivanhoe Newswire) -- A new study published in the New England Journal of Medicine reveals a new strain of leprosy has surfaced in the Southern United States.

Leprosy is a chronic, mildly contagious disease of tropical and subtropical regions with a long and extensive history. Until the 20th century, infected people were ostracized from society or at best segregated and cared for in isolated leper colonies. Today, the disease is entirely curable through multidrug therapy, though tissue damage caused before drug treatment cannot be reversed. Some 600,000 new cases arise every year, mostly in Asia, Africa, Central and South America, and the Pacific Islands. About 60 percent of new cases occur in India.

An intercontinental research team has established the connection among leprosy infection in Americans and direct contact with armadillos. In a group effort between the Global Health Institute at EPFL in Switzerland and Louisiana State University, clear  confirmation was found that a never-before-seen strain of Mycobacterium leprae has appeared in the Southern United States and that it is spread through contact with armadillos carrying the disease.

There are, in all, about 150 cases of leprosy in the United States annually. A majority of these victims have worked overseas, in foreign countries or in areas in which leprosy is widespread, making it probable that they might have obtained the detrimental disease while outside the U.S. However, one-third of all the patients infected appear to have contracted the disease locally.

"There is a very strong association between the geographic location of the presence of this particular strain of M. leprae and the presence of armadillos in the Southern U.S.," Stewart Cole, head of the Global Health Institute in Lausanne and world-leader in the field of genomics of leprosy bacilli, was quoted as saying. "Our research provides clear DNA evidence that the unique strain found in armadillos is the same as the one in certain humans."

These results encouraged researchers to affirm that "frequent direct contact with armadillos and cooking and consumption of armadillo meat should be discouraged."  The study additionally advised that armadillo range growth should be observed and monitored.

It is unknown precisely why armadillos contract and carry leprosy. While their low body temperature makes them ideal incubators for the bacteria, there are further aspects such as immune deficiency that additionally play a role. Correspondingly, the bacteria assault the extremities of humans because our core body temperature is too high for a general infection, and more than 90 percent of humans who come into contact with the disease instinctively fight it off.

"The last thing we want is to induce panic in the population and incite a slaughter of armadillos. The best way to combat further infection is through education and prudence," says Cole.

SOURCE: New England Journal of Medicine, April 28, 2011