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 and Prevention (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.
Untreated, Hansen’s disease causes disabilities over time, with the peripheral nerves affected and the fingers and toes becoming numb. Multibacillary Hansen’s disease, the more serious version, also causes skin lesions, nodules, plaques and nasal congestion. With eye involvement, corneal ulcers and sometimes blindness can occur.
According to the CDC, there are between 100 and 200 new cases of leprosy reported in the U.S. every year. A study just released from the Keck Medical Center at the University of Southern California looked at 187 leprosy patients treated at its clinic from 1973 to 2018 and found that most were Latino, originating from Mexico, where the disease is somewhat more common, and that there was on average a three-year delay in diagnosis, during which time the side effects of the disease — usually irreversible, even with treatment — began to occur.
Leprosy is still more prevalent in Central America and South America, with more than 20,000 new cases per year. Given that, there is certainly the possibility of sporadic cases of leprosy continuing to be brought across our southern border undetected.
And it seems only a matter of time before leprosy could take hold among the homeless population in an area such as Los Angeles County, with close to 60,000 homeless people and 75 percent of those lacking even temporary shelter or adequate hygiene and medical treatment. All of those factors make a perfect cauldron for a contagious disease that is transmitted by nasal droplets and respiratory secretions with close repeated contact.
I am much more concerned about the permanent disabilities that come with leprosy — given that 2 million to 3 million people are affected worldwide — than I am with the associated stigma. Nevertheless, leprosy appearing among the homeless in L.A. is a sure recipe for instant public panic.
Marc Siegel M.D. is a professor of medicine and medical director at Doctor Radio at NYU Langone Health. He is a Fox News Medical Correspondent. Follow him on Twitter @drmarcsiegel.