A Mysterious Flesh-Eating Germ Is Causing An Epidemic In Australia

A Buruli ulcer often starts as a painless bump — but within months, it can destroy muscles, tendons, and even bone.

Cases of Buruli ulcer were once considered rare in Australia, but now they're happening at epidemic levels.

World Health Organization / Via who.int

In the last two years, there has been an explosion of cases in the southeastern state of Victoria. In 2017, there were over 250 cases of the flesh-eating disease, which was a 51% increase from the year before. In 2016 there were 182 cases, which was also higher than normal.

The recent spike in cases is a "rapidly worsening epidemic" that requires "urgent scientific response," according to an article published in the Medical Journal of Australia on Monday. The authors of the article did not respond for comment.

The Buruli ulcer (pictured above, in its early stages) is a chronic infection that slowly leads to erosion of the flesh if it's not treated. It is caused by the bacterium Mycobacterium ulcerans, which belongs to the same family of germs that cause tuberculosis and Hansen's disease (also known as leprosy), according to the World Health Organization.

The condition was first observed in the 1940s so it has been around for decades, Dr. Daniel Eiras, assistant professor of infectious diseases and immunology at NYU Langone Health, told BuzzFeed News. There are approximately 2,000 cases around the world each year, and most of these occur in West or Central Africa. Buruli ulcer has been reported in at least 33 countries, but cases are uncommon in the US.

"The difference here is that it's not well explained why we're seeing an increase of cases in Australia whereas in essentially the rest of the world, we're seeing a decrease in cases," Eiras said.

Researchers think the bacteria might circulate in contaminated water, possibly infecting people via inhalation or small cuts or abrasions on the skin. Or it might be transmitted via insects or be carried by small mammals, such as native possums in Australia — but no one really knows.

The ulcer typically starts as a painless bump on the skin. If left untreated, it can eventually destroy soft tissue and cause permanent disfiguration or disability.

The bump may initially look like a bug bite or pimple, but it is usually painless and it doesn't itch. The main characteristic is that it progresses very slowly and doesn't heal, Eiras said, most likely because it weakens the immune system or prevents it from functioning properly. The infection often affects the arms and the legs, but it still isn't clear why this happens.

Eventually, the bump will become an ulcer or an open sore, then progress if left untreated. "It will start to become larger, then it will invade the lower tissue and fatty layer under the skin and it may involve the muscle, tendons, and bone," Eiras said. It doesn't usually cause other symptoms such as fever or nausea.

Compared with other flesh-eating bacterial infections that spread quickly and kill tissue, such as necrotizing fasciitis, the Buruli ulcer is much less aggressive. "The bacteria do not really 'eat flesh,' they produce a toxin that dissolves the skin and tissue around it, but this could take weeks to months whereas an infection like staph can progress in a matter of days," Eiras said. It's rarely fatal.

That being said, severe cases of Buruli ulcer can cause permanent disfiguration and disability that significantly alter a person's life, Dr. David Blaney, medical officer with the bacterial special pathogens branch at the US Centers for Disease Control and Prevention (CDC), told BuzzFeed News.

Researchers still do not know how the flesh-eating disease is transmitted or where it comes from in the environment.

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There is a lot of mystery surround this flesh-eating disease. The bacteria that cause Buruli ulcer are from the environment and usually associated with wetlands and stagnant water. However, it has been difficult to isolate the bacteria in the environment, Blaney said. So researchers are still trying to find its "natural reservoir" or source in Australia and other parts of the world.

"There’s speculation that it’s from stagnant water and there’s some correlation with certain rodents and opossums, and that mosquitoes play a role, but none of this has really been clarified," Eiras said. Without a clear understanding of where the disease is from and how it spreads, it's very challenging for health officials to come up with public health strategies to prevent Buruli ulcer epidemics.

"It's definitely a neglected tropical disease and tends to be endemic in poor, rural populations where it is not recognized generally by local health providers so the disease can advance, especially in parts of West Africa," Blaney said.

Buruli ulcers are not always easy to diagnose, but most cases can be treated with antibiotics and surgery. However, these can be costly.

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Most cases can be treated with combinations of antibiotics such as rifampicin and clarithromycin, which have cure rates close to 100%, according to the article. "These are not typical antibiotics that someone might get if they go to their primary care doctor," Eiras said.

According to the article's authors, these medications are also not covered by the Pharmaceutical Benefits Scheme, a government program that provides subsidized medication to Australians.

Treatment may also require surgeries and other procedures such as skin grafts, Blaney said, which can vary depending on how much tissue has been destroyed. Between the medication, hospital visits, procedures, and lost productivity, it all adds up. The average cost of treatment for a Buruli ulcer infection is about $14,000, according to the article.

"The emotional and psychological impact on patients and their carers is substantial," the article's authors wrote. Therefore, early diagnosis and treatment is crucial. But this can be difficult because the symptoms progress so slowly. "People generally present fairly late with severe disease because the sore doesn't hurt and people just think it will go away," Blaney said.

Researchers are calling for increased funding to conduct research that will help stop the spread of Buruli ulcer — both in Australia and around the world.

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"It's one of those diseases that really needs more research to determine how it’s transmitted and the actual numbers of people affected by it because we still don't know," Blaney said.

The authors of the study called on local, regional, and national governments to assist with funding to better examine the environment, local flora and fauna, human populations, and other factors related to the Buruli ulcer so researchers can better understand how to prevent it.

"It is only when we are armed with this critical knowledge that we can hope to halt the devastating impact of this disease through the design and implementation of effective public health interventions," the article authors wrote.