Leprosy

Leprosy, a bacterium called Mycobacterium leprae, is a disease that has been with humans for millennia. Records of people suffering from the symptoms of leprosy can be found as far back as 600 B.C. It was bound in ancient Egypt, it was contracted by the armies of Alexander the Great, and it was brought to Europe after the Crusades. During the Middle Ages, leper colonies could be found throughout Europe until the bubonic plague, another bacterium, wiped out about a third of the population. Though leprosy is rare in the United States and Europe (only about 6000 lepers are in the U.S. and most are in Texas and Louisiana), it is very common in countries such as India and Brazil.

Leprosy is an odd bacterium. Scientists have had little luck in culturing it outside a living animal. The bacterium lives best at temperatures slightly lower than most mammals. Its mode of transmission is not well understood. Though people may contract leprosy, they rarely exhibit major symptoms, which are patches of dry skin that loose feeling due to nerve damage, grainy ulcerating lesions on hands, feet, and back, and a slimy discharge from the nose. Parts of the body, such as fingers, toes, and ears, may be lost, but this is not directly due to the disease, but due to damage caused because the victim has lost feeling in those areas.

A recent Discover magazine article, “Where Leprosy Lurks” (November 2000), discusses the research of leprosy and where that research may lead. Armadillos have been used extensively in leprosy research because the animals not only readily contract the disease, they also show symptoms far worse than humans. This may be due to the fact that armadillos have a body temperature slightly lower than most mammals. Organs that remain untouched in the worst human cases were loaded with bacilli in armadillos. It has been shown that armadillos can pass leprosy to humans, but that the likelihood of an epidemic is quite low.

Fortunately leprosy is curable, though the disfigurements that results from the disease are not. The World Health Organization (WHO) has announced that leprosy is no longer a significant public health concern due to their success with in treating leprosy. This has had the effect of reduced funding for leprosy research. However, this announcement may be premature considering other research which shows that the bacterium that causes leprosy and the virus that causes AIDS may cross-react, making patients with one disease more likely to contract the other. It is possible that as the AIDS epidemic grows, a leprosy epidemic may follow.