About a week after Steven Mikac began taking antibiotics for the strange spot on his leg, the flesh around his ankle started to tighten and swell. The moist orifice of a wound opened up and took the form of a small bullet hole. A plug of tissue had gone missing—dissolved into pus and slime. Walking was excruciating. Working, unbearable. In early October of last year, Mikac showed his ankle to a colleague at the hospital where he works in Melbourne, in the Australian state of Victoria. She suggested that it might be Buruli ulcer—a disease caused by a strain of flesh-eating bacteria.
Though Mikac had seen local television reports about an outbreak of this tropical disease in Victoria, it sounded so freakish, so unlikely, that he hardly considered it a possibility. But like hundreds of Australians before him, he was about to become all too familiar with Buruli, a slow-moving horror show that has proved, in many ways, even more baffling to infectious-disease researchers than the novel coronavirus. After decades of research, scientists still aren’t certain who, or what, is spreading this strange malady around the world.
In late October, Mikac met me inside the infectious-disease ward at the hospital where he works and is now a patient. He is a soft-spoken man of 54 with the body of an aging rugby player. He was dressed in shorts and flip-flops. A bandage had been slapped on his left ankle. “It was just a little spot, but I felt there was something different about it,” he said.
We were soon called into an exam room where Mikac’s white-haired, bespectacled doctor, Paul Johnson, greeted us. Johnson has been studying Buruli cases in Australia for decades, and he sees every new case as a chance to crack the disease’s enigma. A few weeks earlier, Mikac had divulged to Johnson one telling clue. His parents own a beach house in the town of Rye, on the Mornington Peninsula south of Melbourne. He had recently helped them out by doing brushwork on the property, and had likely returned to the city with the usual scratches and mosquito bites.
Johnson’s ears had perked up at that. Mikac had been inside a Buruli hot spot, a place where caseloads were far higher than in surrounding areas, and Mikac had been doing the kinds of outdoor activities that notch up a person’s risk. Johnson confirmed Mikac’s diagnosis with a DNA test. The process is more traumatic than one might expect: He had to plunge a cotton swab into the maw of Mikac’s open wound and scrape out the gunk inside as Mikac cringed in pain. Johnson put Mikac on two powerful antibiotics, clarithromycin and rifampicin, which turned Mikac’s urine the color of orange Fanta.
“What you’ve got—the infection is that big,” Johnson said as he sketched a circle around the wound, like the flanks of a small volcano. “But it’s going to get bigger.” He warned Mikac that the antibiotics had shut down Buruli’s defenses, and now the body would launch an attack on the infected tissue. The pus was building up under the skin, and it was about to blow. “Once it breaks through,” he said, “it will feel a lot better.”
Buruli gets its name from a former county in Uganda on the western bank of the Victoria Nile, which emerges from Lake Victoria and flows north toward Sudan. Apart from their shared British imperial history, the two Victorias have little in common. Uganda is steamy and tropical, sitting squarely on the equator; the temperate state of Victoria, in southern Australia, lies 1,000 miles south of the Tropic of Capricorn. Buruli is said to be a disease of poverty, springing from swamps and river basins, but southern Victoria is Pinot Noir country, perched on the precipice of drought.
Since Buruli’s formal description in the mid-20th century, medicine has paid relatively little attention to a condition that, however cruel, primarily afflicts Africa’s poorest residents. Untreated, the pathogen slowly worms its way under the flesh before breaking through the surface, maiming and disfiguring its victims. Their necrotic limbs reek of rot. Although they rarely die of the disease, they are sometimes ostracized in their villages, left jobless and destitute.