How do armadillos factor in?

Some nine-banded armadillos in the southern United States, including in Florida, are also naturally infected with the bacteria that causes leprosy. The CDC say it’s possible that contact with the animal could cause a human to get infected although the risk “is very low” and unlikely. The public health agency still cautions people to avoid armadillos when possible.

“There are pockets where nine-banded armadillos appear to carry this particular strain of Mycobacterium leprae that also appears in humans but we don’t know how it gets from armadillos to people. But when they tested the armadillos in different pockets, they showed that for whatever reason, armadillos in Central Florida, as well as five or six other locations, harbored the strains of Mycobacterium leprae that people get,” said Dunn, the expert at the ADCS Orlando Dermatology Residency Program

But in some other U.S. locations where people and nine-banded armadillos also mingle, and where there are no reported cases of leprosy, those armadillos didn’t harbor the Mycobacterium leprae strain.

“The transmission is really poorly understood,” Dunn acknowledged.

Is leprosy endemic in Florida?

The research report published in the CDC journal indicates that there’s growing evidence leprosy has become endemic in Florida, according to a report published recently in Newsweek.

The report noted that many of the recent cases reported in the eastern United States, including Georgia and Central Florida, lacked typical transmission routes, such as traveling to a country where the disease is widespread and having contact with armadillos.

“Endemic in and of itself is a hot word,” Dunn said, concurring with the research report. “By definition, the CDC defines endemic disease as the constant presence of a disease or an infectious agent within a given geographic area or population group that is neither spiking nor decreasing. It’s just kind of like present. The idea of endemic leprosy looks like it is endemic in certain pockets of the United States and I would say that Central Florida is included in that.”

The report published in Newsweek noted that there “is some support for the theory that international migration of persons with leprosy is a potential source of autochthonous transmission.” It also noted that while leprosy cases are increasing, the rates of new diagnoses among people born outside of the U.S. have declined since 2022.

Who is most susceptible?

The age range of people diagnosed with leprosy in the research studies have been 9 to 75. But most patients tend to be older than 50, Dunn said. “As you get older, your immune system starts to shift and change and your susceptibility to particular things becomes increased.”

Why are most people immune?

Despite the biblical age of this disease, experts remain stumped as to why 95% of the population has a natural immunity to leprosy.

“The classic mantra for leprosy is that you need a susceptible patient, you need prolonged contact, and you need a sufficient bacterial load,” Dunn said. In the vast majority of patients, when the disease invades the body’s skin and nerves, the immune system recognizes the foreign entity and attacks it, nullifying it. In 5% of the population, these individuals don’t have the genetic makeup or the genes that are key to recognizing this bacteria and thus fight it, Dunn said. “It’s a genetic polymorphism or it’s a genetic trait that people inherently have, but we don’t know exactly why.”

Is there a vaccine for leprosy?

A vaccine can’t be formulated because the bacteria is so slow replicating that scientists have yet to even culture it in a petri dish, according to Dunn.

“It’s what’s called a non-culturable disease. We know it exists. We’re able to get what’s called a PCR and test and prove its existence, but we’ve never been able to culture it because it replicates so slowly, and that’s part of the challenge with these diagnoses that we have in the United States,” he said.

Is contact tracing possible?

Contact tracing, which became a household phrase during the COVID pandemic, is next to impossible to conduct for leprosy to pinpoint the origin of its transmission.

“We’re talking about an exposure that occurred years ago — 5, 10, 15, 20 years ago, right? So that’s different than something like COVID where you can walk back a week to two weeks and discover where it was that the contact occurred. But for leprosy, whenever you’re trying to figure out where it happened it’s hard to figure out exactly where it happened,” Dunn said.

Are there travel advisories?

The CDC has not issued any travel advisories for Florida or other states due to leprosy, the public health agency’s website states.

A breakdown of leprosy cases in Florida

Florida has confirmed 203 cases of leprosy since 2013 and 11 of them were in South Florida, according to the state’s web-based reportable disease surveillance system. While state officials still don’t know where many of the infections originated, they’ve determined that at least 63 of the 203 cases, or about 31% of the reported cases, were acquired in Florida. Nineteen of the cases, or 9%, were acquired in another country.

So far, Florida has confirmed three cases of leprosy this year, state data shows. A look at the cases:

▪ One person in Sumter County who is between the ages of 20-24. State health officials don’t know if the person was infected in Florida, another state or another country.

▪ One person in Polk County who is between the ages of 25-29. State health officials say the person acquired the infection outside of the U.S.

▪ One person in Volusia County who is between the ages of 55-59. State health officials believe the person acquired the infection in Florida.

When was the last time South Florida recorded leprosy cases?

▪ In Miami-Dade, the most recent confirmed leprosy case was in 2014. A person between the ages of 50-54. State health officials don’t know where the person was infected.

▪ In Broward, the most recent confirmed leprosy case was in 2021. A person between the ages of 50-54 was infected outside of the U.S.

▪ In Palm Beach County, the most recent confirmed leprosy case was in 2023. A person between the ages of 65-69 was infected in Florida.

▪ Monroe County hasn’t recorded a leprosy case in more than 10 years. The last time a case was reported in the Florida Keys was in 2010. The case involved a person between the ages of 55-59 who acquired it in Florida.

©2024 Miami Herald. Visit at miamiherald.com. Distributed by Tribune Content Agency, LLC.