Armadillos, with their distinctive shells, are found across the Americas, particularly in the southern United States and parts of Central and South America. While often perceived as harmless, they can interact with human environments, raising questions about their potential to carry and transmit diseases.
Primary Disease Link
Armadillos are known to carry Mycobacterium leprae, the bacterium responsible for leprosy (Hansen’s Disease). They are among the few non-human animals known to naturally harbor this bacterium and serve as a natural reservoir, particularly the nine-banded armadillo (Dasypus novemcinctus) found in the Americas.
The scientific link between armadillos and human leprosy cases was first established in the 1970s. Studies in regions like the southern United States, including Texas, Louisiana, Florida, and Alabama, have identified identical strains of M. leprae in both wild armadillos and human patients, confirming zoonotic transmission. Approximately 15-20% of armadillos in some areas of Florida, for example, carry the bacteria. This natural susceptibility in armadillos is partly attributed to their lower body temperature, which provides an optimal environment for the bacterium to thrive.
Other Potential Concerns
Beyond Hansen’s Disease, armadillos can carry other pathogens, though less commonly. Salmonella bacteria can be present in their digestive tracts and feces, posing a risk of transmission through environmental contamination. This can cause symptoms like diarrhea, fever, nausea, and vomiting.
Armadillos may also indirectly play a role in the transmission of Chagas disease, caused by the parasite Trypanosoma cruzi. While armadillos themselves do not directly transmit Chagas disease to humans, their burrows can provide habitats for infected triatomine bugs, often called “kissing bugs,” which are the vectors for the parasite. These bugs transmit the parasite through their feces, which can enter the human body via a bite wound or mucous membranes. Although rare, armadillos, like any mammal, can contract and transmit rabies, typically through bites or scratches. However, their low body temperature makes them less suitable hosts for the rabies virus compared to other wildlife.
How Diseases Spread and Risk Factors
Transmission of diseases from armadillos to humans primarily occurs through direct contact. For Mycobacterium leprae, this usually involves handling the animals, their blood, tissues, or bodily fluids, or through contact with their droppings. Bites and scratches from an armadillo can also pose a risk of transmission for various pathogens.
Consumption of undercooked armadillo meat is another potential route for disease transmission, including M. leprae and Salmonella. Environmental contamination, such as contact with soil or water tainted by armadillo feces, can lead to Salmonella infection. While the overall risk of contracting diseases from armadillos is low for the general public, it increases significantly for individuals who frequently interact with them, such as hunters, trappers, researchers, or those in common armadillo habitats.
Staying Safe Around Armadillos
Minimizing health risks from armadillos involves simple preventative measures. It is advisable to avoid direct contact with armadillos, whether they are alive or dead. This includes refraining from handling them or their carcasses, even if they appear injured. Children should also be educated about the importance of observing wildlife from a safe distance.
When outdoors where armadillos are present, especially when disturbing soil, wearing gloves is advisable. Hands should be thoroughly washed with soap and water after any potential contact with armadillos, their burrows, or areas where they have been active. If armadillo meat is consumed, it must be cooked thoroughly to eliminate potential pathogens like M. leprae and Salmonella.