The Leprosy Research Institute in Astrakhan, Russia was known as the Center for Leprosy in the days of the former Soviet Union. For some reason, there is a stuffed armadillo on display there. Russia, however, is not a natural habitat of armadillos, which are indigenous to the Americas, in particular, from the southern part of North America to Argentina in South America. I wondered what the armadillo was doing in Astrakhan, so far away from its home.

Leprosy is an infectious disease caused by the bacillus Mycobacterium leprae, or M. leprae for short. Besides humans, three species of monkeys, namely, the common chimpanzee, the crab-eating macaque, and the sooty mangabey, as well as one armadillo species, the nine-banded armadillo, can contract leprosy. There are approximately 20 species of armadillos, but only one, the nine-banded armadillo, is known to be highly susceptible to the disease and the only one that contracts the disease. For this reason, this armadillo has been used in research and experimental trials in many countries to develop a vaccine. Thereafter, it was found that nude mice with immune dysfunction due to spontaneous mutation could also be infected and show symptoms of leprosy, and now they are primarily used in leprosy research.

Research indicates that an early form of leprosy existed in East Africa some 10 million years ago. The standard interpretation is that leprosy was brought to the New World (North and South America and Oceania) by migration from the Old World. In fact, epidemics later occurred in Canada, the United States, and the countries of South America. Furthermore, a bacillus recently found in Central America is now considered to be another cause of leprosy. This strain is said to have accompanied the first humans who crossed the Bering Strait and arrived on the American continent, and armadillo infection has also been attributed to it.

In the United States, leprosy is considered to be a disease of the past. Many may think it is no longer an issue and it doesn’t matter today. Actually, in the United States, close to one hundred new cases of leprosy are found every year. One source of infection is considered to be none other than the nine-banded armadillo.