For years, about 150 Americans acquired leprosy annually, but doctors had no idea where about one-third of the cases came from. (Two-thirds were acquired overseas.) In a bizarre twist (bizarre, at least, for those of us who do not follow current events in leprosy), today in the New England Journal of Medicine American and Swiss researchers concluded that these leprosy cases, most occurring in Texas and Louisiana, were transferred from wild armadillos. (Researchers say mere contact with an armadillo is unlikely to transfer the disease. Most people acquire it, they believe, by ingesting raw armadillo meat; barbecued armadillo and armadillo chili are well-known dishes in those states.) Even so, 150 cases is a very small number, which begs the question: can leprosy be eliminated?
In 1991, at the World Health Assembly, WHO members voted to eliminate leprosy by the year 2000. (They defined elimination as less than 1 case per 10,000 people.) Fourteen years later, two leprologists published a review of this effort in the Bulletin of the World Health Organization. The authors found that the campaign had been successful in distributing highly effective antibiotics, lowering the number of cases worldwide, and in reducing the social stigma of leprosy in many countries. But the number of new cases each year did not decline, suggesting that vaccines were not enough. The leprologists suggest that the bacterium that causes leprosy may be too hardy to easily eliminate, as it can incubate in the body for a number of years before detection, and be passed on by people who are unaware they've been infected. They also recommend adjusting strategies to treat leprosy as more of a long-term chronic disease, instead of merely an short-term infection.