Armadillos can carry the bacterium that causes leprosy. This connection, while scientifically established, involves specific conditions that determine the risk to humans. Understanding the disease itself and the biological factors that link it to armadillos helps clarify this relationship.
Understanding Leprosy
Leprosy, also known as Hansen’s disease, is a long-term infection caused by a slow-growing bacterium called Mycobacterium leprae. This bacterium primarily affects the skin, peripheral nerves, upper respiratory tract, eyes, and testes. Symptoms can develop slowly, sometimes taking years or decades to appear after exposure.
If left untreated, the nerve damage can lead to a lack of sensation, muscle weakness, and potential disfigurement. Fortunately, leprosy is curable with a combination of antibiotics, known as multidrug therapy. Early diagnosis and treatment are important for recovery and prevent complications.
The Armadillo Connection
Armadillos are one of the few species, besides humans, known to naturally host Mycobacterium leprae. This susceptibility is largely attributed to their body temperature, which is lower than most mammals, typically ranging from 30-35°C (86-95°F). This cooler internal environment provides an ideal growth condition for Mycobacterium leprae, which thrives at temperatures around 33°C.
Scientists believe that armadillos acquired the bacterium from humans centuries ago. The nine-banded armadillo (Dasypus novemcinctus) is the specific species implicated in this connection, and these animals are common across the southern United States, including states like Texas and Florida. Studies have shown that in some areas, up to 15-20% of wild armadillo populations may carry the bacterium.
Potential for Human Exposure
Transmission of Mycobacterium leprae from armadillos to humans is possible, primarily through direct contact with an infected animal. This can occur during activities such as handling, hunting, or processing armadillos. The bacterium can enter the human body through cuts or scrapes on the skin.
Another less common route of exposure is through the consumption of undercooked armadillo meat. While the risk is generally low, frequent consumption of undercooked armadillo meat increases risk. Despite these routes, the overall risk of contracting leprosy from armadillos is low for most people. Over 95% of the human population has a natural immunity to Mycobacterium leprae, and the bacterium is quite fragile, surviving only for a short time outside of a host.
Protecting Yourself
To minimize exposure to Mycobacterium leprae from armadillos, avoid direct contact. This includes refraining from handling live, sick, or dead armadillos. If contact is unavoidable, such as during removal from your property, wear gloves.
For individuals who consume armadillo meat, ensuring it is thoroughly cooked significantly reduces the risk of transmission. Heating the meat to appropriate temperatures will destroy the bacterium. While the overall risk is low, these simple measures provide added protection.