Lady Gaga, Leprosy and Armadillos! Oh My!

The medical (and pop-culture) significance of armadillos

In late July 2015, Lady Gaga dropped nearly $300,000 on 3 pairs of armadillo boots by late fashion designer Alexander McQueen. (At a hundred grand a pair, these boots make Louboutins look like a steal.) Gaga was apparently ecstatic with her purchase--which benefited UNICEF--and was pictured wearing the boots which look a lot like armadillos. Despite their appearance, however, the boots aren't actually made of armadillos.

Apparently, they're constructed from python leather and wood. Originally, the boots were priced at $10,000 each.

Lady Gaga's purchase got me thinking about armadillos and their medical significance. Specifically, armadillos are the only species other than humans to naturally harbor Myobacterium leprae, the bacteria which causes leprosy or Hansen's disease.

Armadillos are animals found in South America, Central America, and the Southeastern United States.  Armadillos are about the size of cats, and in evolutionary terms, are similar to sloths and anteaters.  Armadillos possess short limbs, claws and are encased in a hard outer shell or carapace.

About 40 years ago, two researchers named Kircheimer and Storrs discovered that nine-banded armadillos, which are found in the United States, can be infected with leprosy and make excellent experimental models for leprosy research.

Armadillos make good experimental models for leprosy research for several reasons.

First, they're relatively large and have long life spans. Second, their core body temperatures are low, and Myobacterium leprae has a predilection for cooler temperatures which explains why leprosy normally affects human fingers and toes. (Your fingers and toes are cooler than your torso.) Third, as with humans, Myobcaterium leprae can invade nerve cells in armadillos and thus cause extensive sensory and motor damage.

In the United States, about 100 cases of leprosy are diagnosed each year--mostly in the South, California and Hawaii. Whether any of these cases are attributable to armadillos is debatable; however, a recent spate of leprosy cases in Florida, where armadillos live, has some people concerned. In fact, some experts believe that up to 64 percent of new leprosy cases in the United States are caused by exposure to armadillos. Thus, it's probably a good idea to keep away from armadillos.

Leprosy isn't very contagious, and it takes a long time to develop the disease--anywhere from  2 to 10 years. Children who are exposed long term to family members who are heavy shedders of the bacilli are most susceptible. Of note, leprosy is spread through nasal secretions. Leprosy is diagnosed by skin scrapings and biopsy.

Here are some clinical symptoms of leprosy:

  • skin lesions or sores which are lighter in color than surrounding skin;
  • numbness in the hands, feet, legs and arms;
  • muscle weakness.

Because leprosy messes up nerves, skin lesions typical of the disease lack sensitivity to touch, pain, and heat.

Moreover, these skin lesions don't heal.

Leprosy comes in two forms: tuberculoid and lepromatous. Diagnosis of either type of leprosy is based on a Lepromin skin test. Although both types cause sores, lepromatous leprosy is associated with a worse prognosis. Specifically, people with the lepromatous form of leprosy can go on to experience profound nerve and muscle damage and disfigurement (loss of hands and feet).

The key to successful treatment of leprosy involves early diagnosis. With early treatment, the severity and spread of the disease is limited, and a person with the disease can go on to live a healthy life.

Although some newer strains of Myobacterium leprae are drug resistant, which poses particular risk among those in developing nations where leprosy is more prevalent, most people can be effectively treated for the disease. Furthermore, people on long-term antibiotic treatment can no longer infect others.

Here are some antibiotics used to treat leprosy:

  • dapsone (first-line treatment)
  • rifampin
  • clofazimine
  • clarithomycin
  • minocyclin
  • fluoroquinolones

Typically, a combination of these antibiotics is used to treat leprosy, and a person with leprosy needs several years of treatment. Of note, the inflammation that accompanies leprosy is treated with aspirin, steroids, and thalidomide.

Rest assured, the chances that you'll develop leprosy--even if you were to encounter an errant armadillo--are low. Moreover, we fortunately no longer isolate people with leprosy in leper colonies. Nevertheless, if you were to develop symptoms suggestive of leprosy, contact a physician immediately.

Selected Sources

Article titled "The armadillo as an animal model and reservoir host for Myobacterium leprae" by G Balamayooran and co-authors published in Clinics in Dermatology in 2015.  Accessed on 7/29/2015.

Brooks GF, Carroll KC, Butel JS, Morse SA, Mietzner TA. Chapter 23. Mycobacteria. In: Brooks GF, Carroll KC, Butel JS, Morse SA, Mietzner TA. eds. Jawetz, Melnick, & Adelberg's Medical Microbiology, 26e. New York, NY: McGraw-Hill; 2013.  Accessed July 29, 2015.

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