The Scourge of TB
In South Africa, good intentions and poor follow-through are helping to spread deadly drug-resistant tuberculosis.
Eight-year-old Kabela sits under a eucalyptus tree outside the Sizwe Hospital School in Johannesburg, South Africa, and tells me about his life. “We write nicely, and we do the work, and we come play, and we play the jungle gym, and we go for break and we come back … We take the homework books. We come again tomorrow.”
When Kabela was born, his mother passed along her HIV infection, which would have been a death sentence a few years earlier. Instead, Kabela has the plump, fresh face of a patient on antiretrovirals. But before his mother died, she also passed along the extensively drug-resistant tuberculosis (XDR-TB) infection that killed her. Kabela’s TB, like his mother’s, almost certainly is a death sentence. Last year, doctors at Sizwe Hospital, where Kabela is quarantined, discovered a hole in his lung the size of a tennis ball. Though he brims with energy and charm and dances to even the mere suggestion of music, he has little chance of leaving this hospital alive.
In 2006, a study from the small town of Tugela Ferry, South Africa, shocked the world with news of an outbreak of extensively drug-resistant tuberculosis that had killed more than 98 percent of the patients that it infected, many of whom had AIDS. Doctors detected XDR-TB after noticing that AIDS patients, who are particularly vulnerable to tuberculosis, were dying even after being treated for TB and starting antiretrovirals.
Each year, the number of tuberculosis cases increases in South Africa—in fact, as the disease nearly tripled in prevalence in the past decade, it became one of the top killers of South Africans. But the resurgence of tuberculosis is not limited to South Africa. India and China have the largest numbers of tuberculosis cases, and multi-drug-resistant tuberculosis (MDR-TB) has been found in nearly every country, with XDR-TB in at least 57 countries. A major hurdle in treating MDR-TB and XDR-TB is that the course lasts up to two years and is 200 to 1,000 times more expensive than regular TB drugs. Even with treatment, multi-drug-resistant tuberculosis kills 30 percent of those infected, while XDR-TB kills roughly 60 percent. Unless the world gets ahead of the epidemic, drug-resistant forms of tuberculosis may not only kill hundreds of thousands, but also render moot global efforts to roll out HIV/AIDS antiretrovirals.
In the 1990s, as new drug-resistant strains of TB reawakened concern about an ancient foe, global health authorities launched a treatment plan called DOTS. The program calls for “directly observed therapy,” meaning that a patient must be observed taking medication each day by a health worker for the six-month course. Treatment is provided under a government commitment that includes not just a steady drug supply, but diagnostics and monitoring as well. Designed to ensure that people complete their treatment regimen, the program—when it is properly implemented—works very well at both curing patients and preventing the rise of drug resistance. But the DOTS program also highlights a deadly paradox: in places like South Africa, where patients often stop showing up for (or “default from”) treatment, and follow-up is spotty due to lack of resources, the result of greater access to drugs can be rising rates of drug resistance.
“It’s been realized that under perfect conditions, DOTS works, but not really in real-life circumstances,” says Martie van der Walt, acting director of the tuberculosis-epidemiology group of South Africa’s Medical Research Council. In South Africa, 8.5 percent of all TB patients default from treatment, and the overall cure rate is a dismal 65 percent, well below the World Health Organization’s target of 85 percent. If these default or uncured patients become resistant to first-line drugs, they can spread their strain of the disease to their communities, a phenomenon that is fueling South Africa’s epidemic.
The first new TB drugs in 40 years are in the pipeline, but they will not be available for at least two years, and they won’t necessarily solve the current problems. Indeed, according to Mario Raviglione, director of the WHO’s Stop TB Department, unless these new drugs are protected from misuse in ways that the old ones were not, “we lose them.”
For now, Kabela shuttles between school and Sizwe Hospital’s Ward Six. “He’s taking his medicine faithfully because he knows it means going home,” says Priya Singh, the school headmistress. No one has had the heart to tell him that he will likely die in the same hospital that he has been in for four years, in part because the world adopted a good system that many countries lacked the wherewithal to implement.