Is a Dark Ages disease the new American plague threat?

Diseases are reemerging in some parts of America, including Los Angeles County, that we haven’t commonly seen since the Middle Ages. One of those is typhus, a disease carried by fleas that feed on rats, which in turn feed on the garbage and sewage that is prominent in people-packed “typhus zones.” Although typhus can be treated with antibiotics, the challenge is to identify and treat the disease in resistant, hard-to-access populations, such as the homeless or the extremely poor in developing countries.

I also believe that homeless areas are at risk for the reemergence of another deadly ancient disease — leprosy, also known as Hansen’s disease. Leprosy involves a mycobacteria (tuberculosis is another mycobacteria) that is very difficult to transmit and very easy to treat with a cocktail of three antibiotics.

Yet according to the Centers for Disease Control (CDC), there are more than 200,000 new cases of leprosy reported in the world every year, with two-thirds of them in India, home to one-third of the world’s poor. The poor are disproportionately affected by this disease because close quarters, poor sanitation, and lack of prompt diagnosis or treatment easily can convert a disease that should be rare to one that is more common.