Scientists are scrambling to understand rising cases of Buruli ulcer in Australia – and of the role humans and possums play in spreading it.
Adam Noel thought it was just a mosquito bite. He’d noticed the slightly raised, red mark on the back of his ankle about a week before, but it wasn’t getting better. The doctors thought it was some kind of skin irritation. Two more weeks went by, but his heel now had a hole in it. “There is something very strange going on,” he thought, so he drove himself to Austin Hospital in Melbourne to have it looked at again.
It was April 2020 and the coronavirus pandemic had a firm grip on Australia. Staff were overwhelmed. The doctors told him the wound would heal up soon enough. Instead, after a few more days, you could see his Achilles tendon through the now table tennis ball-sized hole in his flesh. So back to hospital he went, this time to St Vincent’s, one of Australia’s leading hospitals. They kept him in for about a week taking biopsies before finally confirming the cause of Noel’s ordeal. It was Buruli ulcer: a bacterial disease that can cause large open wounds and, if untreated, lead to permanent disfigurement.
It was about six weeks from Noel noticing the mark to getting a definitive biopsy and taking the right medication. The doctors say he could have lost his foot.
Prior to noticing the initial mark, Noel had been doing a lot of work in the garden, digging up the soil to make way for a big shed. “I cut down a bunch of trees that have not been disturbed in 20 years,” he says. “I’m pretty convinced that [getting the ulcer] coincided with disrupting the trees and possum habitat.”
Yes – possums. Scientists believe these fluffy, nocturnal creatures may play a key role in the transmission of the Buruli ulcer to humans. They too suffer from the disease, and the Buruli bacteria – called Mycobacterium ulcerans – is found in high quantities in their faeces. Much natural possum habitat has been lost to development in recent years, bringing possums and humans closer together as the two species vie for space, and quite possibly driving up cases of the disease.
Once a suburban resident, the Buruli ulcer is now inching closer to Melbourne, and doctors and scientists are trying to stop it before it reaches the population of five million people.
A rising threat
Noel lives in Melbourne but his family have a beach house about 100 km (62 miles) away in the Mornington Peninsula. It’s an affluent area which juts out like a leg from the mainland, with the tip of the toe kicking west. A popular holiday destination for city-dwellers, sandy beaches are flanked by colourful beach huts and wooden boardwalks wind through the rolling hills with views of the ocean. Trails lead to places like “Diamond Bay” and along “Millionaire’s Walk”. The houses are big and modern, many with spacious gardens and swimming pools.
It’s not exactly the kind of place you’d expect to hear of a rampant flesh-eating bacteria on the loose, but cases of Buruli ulcer in Victoria tend to be found in this area. Across the state, cases have more than tripled in recent years: in 2014 doctors reported 65 cases; in 2019 there were 299 while last year saw 218 cases.
When a case of the ulcer is suspected, the patient is most often referred to Daniel O’Brien, an infectious disease physician and Buruli ulcer expert who runs a clinic in nearby Geelong. He’s started making the 40-minute ferry ride across the water weekly to see the growing number of patients with the ulcer. He says he sees as many as five to 10 new patients weekly.
The physical impacts are significant – the aggressive ulcer can cause disfigurement, requiring serious surgery and leading to long-term disability
The Buruli ulcer can rapidly destroy skin and soft tissue if not treated with a combination of specific antibiotics and steroids for weeks and, in many cases, months. “No matter how small the lesion, or how big it is, there’s nobody that’s not significantly affected by this disease,” says O’Brien. The physical impacts are significant: the aggressive ulcer can cause disfigurement, requiring serious surgery and leading to long-term disability. “It can really eat away at a whole limb,” says O’Brien, whose patient list includes young children who have needed up to 20 operations to deal with their ulcer.
There’s also an economic impact to this disease. Noel works on the TV soap opera Neighbours and had to take a month off work because the hole in his foot meant he was unable to stand up for any extended period of time. The treatments can leave people feeling very unwell too. Noel’s steroids made him “wound up like a clock”. “I was bloody happy once we stopped,” he says. Seven months on, he still has to take antibiotics. Other patients spoke of the antibiotics causing sickness, oral and vaginal thrush and an upset stomach.
“It’s hard going. It’s very uncomfortable, and very unpleasant,” says Cheryle Michael, a retiree who got a Buruli ulcer on her face in August 2020 and is still taking medication. “The steroids made me so depressed, so tired and unmotivated,” she says. The antibiotics cause stomach issues which make her nervous to leave the house. “I really don’t want to be too far away from my own toilet, quite frankly,” she says.