This summer, news of a rise in leprosy cases sparked concern about this ancient and misunderstood disease. Scientists are studying recent cases of leprosy in Florida that lack traditional risk factors of the disease. The United States reported 159 new cases in 2020, according to a research letter published in the Centers for Disease Control and Prevention, with nearly one-fifth of national cases occurring in Central Florida.
While leprosy is treatable and 95% of people are naturally immune to the disease, it is important for patients and doctors alike to be aware that this rare disease is being transmitted. Norman Beatty, M.D., an assistant professor in the University of Florida’s College of Medicine and a member of the EPI answers some common questions about leprosy.
Q: What is leprosy?
Beatty: Leprosy, also known as Hansen’s disease, is a chronic infectious disease most commonly caused by bacteria called Mycobacterium leprae. It typically causes different types of skin abnormalities and can damage the peripheral nervous system. Not everyone who is infected will develop the clinical disease that results from chronic infection. But for those who do, it can take years after initial exposure for signs and symptoms to appear since the bacteria is slow growing. There are five main types of leprosy: tuberculoid (TT), borderline tuberculoid (BT), mid-borderline (BB) or borderline lepromatous (BL) and lepromatous leprosy (LL). Precisely which one someone develops really depends on the type of immune reaction their body has to the bacteria.
Q: What are symptoms of leprosy? How do I know if I have leprosy?
Most people who develop the clinical disease will have some kind of skin reaction — lesions like papules, macules, or plaques, that are reddish or hypopigmented, which means that part of the skin is lighter in color. Some will have thickened skin or even nodules that develop, especially in the nose, forehead and ears. Since the peripheral nerves can become damaged, some people can develop a loss of sensation. At first there may be a tingling to the touch in the affected region, which we call paresthesia, before it eventually becomes numb and painless, which is known as hypoesthesia. Some people might also experience autonomic dysfunction, which affects the autonomic nervous system and can cause symptoms like abnormal sweating and heat intolerance. Finally, the peripheral nerves, which are the ones outside the brain and spinal cord, become enlarged and palpable.
Q: How is leprosy transmitted? How would I get leprosy?
The transmission of leprosy is an important question here in Florida, because we do not fully understand the complex transmission cycle. Transmission from the nine-banded armadillo to human beings has been reported and likely occurs when the two come into direct or indirect contact. People with a type of leprosy called multibacillary leprosy also have high numbers of the bacteria in their respiratory droplets and nasal secretions. Human to human spread can occur with close contact over prolonged periods of time. There have been cases where someone was infected without coming into direct contact with an infected person or an armadillo. One hypothesis we have is that those handling soil that an armadillo has contaminated may be at-risk for transmission, but more research is needed to better understand that possibility.
Q: What should someone do if they think they have leprosy?
They should bring it to the attention of their primary care doctor, who can do a physical exam and send a referral to talk to a consultant, either an infectious disease provider or dermatologist with expertise in making a leprosy diagnosis.
Q: Is leprosy treatable?
Absolutely. Leprosy is a treatable disease and can be cured. There are several medications that target the bacteria that we can use. It can be a combination of several antibiotics, which will need to be taken for several months or up to one to two years.
Q: What can people do to avoid getting leprosy?
One thing someone can do is avoid close contact with the nine-banded armadillo, which means not handling it or eating it. It is also important to try and keep armadillos away from your home — working with wildlife management services is one way to remove unwanted visitors. It’s also possible for transmission to occur from contact with soil that has been contaminated with the leprosy bacteria. This has not been confirmed at this time, but to be safe, people who garden, work in agriculture or landscaping or otherwise have close contact with soil should protect their hands and extremities with gloves and clothing that would prevent contamination. It is also important to cover any open cuts or scratches from soil contamination. This can prevent bacterial infection in general and is a good practice overall.
Q: What was your reaction to the news coverage on leprosy in Central Florida?
We have been seeing an uptick in locally acquired cases of leprosy here in Central Florida and some parts of North Florida over the last five to ten years. When I read that case report, it wasn’t a surprise to me because we have had several cases here in North Florida. It is important to be aware that we have leprosy being locally transmitted here in our state, so people know to report any symptoms to their doctor.
Q: Is leprosy common now? Why is leprosy in Florida?
I would not say that leprosy is common, although the number of cases acquired within the United States have increased. Florida has the highest rate of known infection in the country, but leprosy is also being transmitted locally in other regions within the Southeast and Texas, for example. The cases correlate with the natural range of the nine-banded armadillo, which is the natural host of the bacteria. More research is needed to better understand who is at risk for leprosy in Florida.
Q: Should I be worried about leprosy? Does leprosy pose a threat?
Leprosy is a rare infectious disease, but awareness in Florida is important. While leprosy is treatable and curable, the longer you experience symptoms the more likely you are to develop chronic issues. This is another reason why early recognition is key, and if you are concerned you may have leprosy you should talk with your doctor.
Q: Any closing throughts?
We need more research to better understand who’s at risk of leprosy and how exactly it’s being transmitted here in Florida.
Written by: Jiayu Liang