Armadillos as transmitters of leprosy

Armadillo form a reservoir for leprosy pathogens

28.04.2011

Armadillos are apparently responsible for leprosy in the United States today. The last survivors of the mammalian family of the so-called armored collateral animals (Cingulata), carry bacteria that can cause leprosy in humans. This report researchers in the online edition of „New England Journal of Medicine“.

The researchers discovered in the study of armadillo a special strain of the pathogen Mycobacterium leprae, which was found both in the animals and in also examined leprosy patients. These bacteria allow transmission of leprosy by the armadillo and are responsible for the fact that even today leprosy disease in the US occur, the researchers write.

Special Mycobacterium leprae detected in armadillos
In the study, the scientists compared the DNA of the bacteria of 33 armadillos from the southern USA with the bacterial DNA of 50 leprosy patients. They were able to detect a special, previously unknown strain of the pathogen Mycobacterium leprae in 28 armadillo and 25 leprosy patients. Their findings confirm that armadillos can infect people with leprosy, the researchers said. The significance of the study is all the clearer, since 22 patients had never left North America in their lives, meaning that other sources of infection outside the US could be virtually ruled out. In addition, eight of the leprosy patients stated that they had direct contact with armadillos. One of the leprosy sufferers even stated that he hunted and ate the armadillos. The mystery of recurrent leprosy in the US seems to be solved. The armadillos are evidently still a reservoir for the leprosy bacteria, which were probably introduced to the Americas by the first European immigrants.

Leprosy used to be one of the most dreaded diseases
Leprosy was one of the most feared infectious diseases worldwide until the late 19th century. It was only after the Norwegian physician Gerhard Armauer Hansen discovered the disease-causing bacterium Mycobacterium leprae in 1873 that progress was gradually made in treatment. The breakthrough finally came in the 1940s with the development of sulfonamide therapy. The use of the still important antibiotic dapsone (DDS) in leprosy therapy was also introduced at this time. Since the 1970s, leprosy has been treated with multiple antibiotic combination therapies, and since 1982, the World Health Organization (WHO) has recommended polychemotherapy for the treatment of the disease. Although the disease has almost been eradicated in most industrialized countries since then, infection in the United States is still a rare occurrence, not as a result of a stay abroad but, as is now clear, in transmission of the pathogens through armadillosis. However, leprosy is far from defeated worldwide anyway. Especially in the poorer developing countries with poor hygiene standards, leprosy still occurs today. WHO estimates that nearly 245,000 people worldwide have leprosy in 2009. However, in this country, leprosy does not represent a particular health threat. In 2010, for example, only two cases were reported in Germany, with the patients having become infected during a stay in Asia. (Fp)

Picture: Dr. Karl Herrmann