Each year Florida documents between two and 12 cases of leprosy, but this year nine cases have already been verified by the state, The Associated Press reported. This higher-than-usual number, health officials said, results from human contact with armadillos.

A chronic infectious disease, leprosy (also referred to as Hansen’s disease) is caused by Mycobacterium leprae. Though it is possible to get leprosy from armadillos, Dr. Richard Truman of the National Hansen’s Disease Program says the “specific mechanisms” for transmission are unknown.

“Long term, close direct contact with the blood or tissue of infected animals would likely pose the greatest risk for exposure,” he told Medical Daily.

The bacterial disease affects the skin, the peripheral nerves, the eyes, and upper respiratory tract. It can incubate for three to five years, and symptoms can take as long as 20 years to appear. This “makes it very difficult” to understand either the risk factors or the specific behaviors that cause a single infection, Truman said.

“Some of our patients have reported hunting or cooking armadillos, but others report that they have never had any direct contact with armadillos,” he said.

Though leprosy ranks among the world’s most feared infections, nearly 95 percent of its population has a natural immunity to the disease-causing bacteria, according to the Department of Health and Human Services. Leprosy also is curable with a multi-drug treatment, reports the World Health Organization, which recorded 180,618 existing cases and 215,656 new cases of the disease worldwide in 2013.

In the U.S., leprosy is rare, with about 150 new cases reported each year. Texas and Louisiana record the highest number of patients. Most Americans get the infection after living or working abroad in leprosy-endemic areas. Still, nearly a third of all patients acquire the disease from local sources in the absence of contact with an affected person, according to a 2011 study published in the New England Journal of Medicine.

This same study, co-authored by Truman, concluded that wild armadillos and many U.S. patients with leprosy are infected with the same strain of M. leprae, suggesting these animals are a natural reservoir for the bacteria. The authors say the disease may be a zoonosis in the southern U.S.

“A zoonosis is an infectious disease carried by animals that is transmissible to humans by natural means,” Truman said, noting that rabies and plague are the most widely known zoonoses.

The most recent diagnosis for leprosy emerged in Flagler County, Fla., three weeks ago. Between 2012 and 2014, Brevard County, known as the Space Coast, recorded 12 cases, while Martin and Okeechobee each recorded a single case.

The Florida Department of Health website states leprosy has been reported in Florida since 1921. The department’s demographic analysis of confirmed or probable cases reported that between 1987 and 1995 over half (57 percent) of the affected people lived in southeast Atlantic Coast counties, with others from counties along the south-central Gulf Coast or mainland. About 75 percent of patients have no known contact. Mara Burger, a spokesperson for the department, advises people “avoid interacting with any wild animals, including armadillos.”

Meaning “little armored one” in Spanish, the word “armadillo” refers to the animal’s shell, which is similar to that of a turtle. Closely related to anteaters and sloths, these mammals live in temperate and warm climates where they primarily consume beetles, ants, termites, other insects, and, less frequently, small vertebrates, plants, and fruit. Though the Centers for Disease Control and Prevention finds the risk of contracting leprosy from an armadillo to be low, the center still warns people to shun these animals.