The spread of the world’s most lethal TB strain in KwaZuluNatal has triggered calls to consider quarantine and forcible medical treatment for people with drug-resistant strains of the disease.
The KwaZulu-Natal strain of extreme drug-resistant TB, XDR TB, is effectively untreatable because it is immune to seven of the nine standard TB drugs available in South Africa. At least three antibiotics are needed in combination to kill the Mycobacterium tuberculosis bacteria that causes TB.
The bacillus has killed 52 of 53 diagnosed patients, including two healthcare workers. It has been detected in 28 other medical facilities and is thought to have spread across the province’s borders.
The XDR strain in KwaZulu-Natal, first identified as multi-drug resistant (MDR) in the mid-1990s, has mutated over the past decade into the untreatable form identified this year. The first known case of XDR worldwide occurred in the late 1990s at Sizwe Hospital in Johannesburg, where several patients who attended the hospital for normal TB care caught the drug-resistant form from another patient. All of them died.
Drug resistance results when people fail to complete the six-month first-line treatment of daily antibiotic cocktails — although treatment failure has been known to occur in patients who take their medicine diligently.
The Medical Research Council estimates that about half the adults with active TB are cured each year, compared with 80% in countries with better resources. Nationally, about 15% of patients default on the first-line six-month treatment. About 10% of TB patients die, largely because of HIV, and no outcome is recorded for many patients.
Second-line treatment can last up to two years, including months of hospitalisation with painful daily antibiotic injections. Almost a third of patients default, and in another 10% the treatment is unsuccessful.
It is these patients whom experts say should be compelled to take treatment or be removed from society until the treatment is successful — or the patient has died.
MDR and XDR TB can be transmitted from person to person and infect someone with ordinary TB. Often increased drug resistance also reduces the fitness of a pathogen. However, KwaZulu-Natal’s XDR strain appears to be as aggressive and infectious as the drug-responsive forms. It also appears to kill faster.
The only way to prevent the spread of XDR TB is to isolate its carriers.
Mary Edginton of the Wits medical school said urgent attention should be paid to public health laws that allow for the quarantining of people with diseases posing a public health risk, such as TB.
In the United States, doctors use similar laws to incarcerate and forcibly treat TB patients when it is considered to be in the public interest. South Africa has similar legislation, but it does not seem to have been enforced for many years, perhaps due to concerns that it is in conflict with the Constitution.
However, some experts say that this is merely a perceived obstacle as the Constitution also guarantees communal rights, including protection from infection and the right to a safe environment.
Karin Weyer of the Medical Research Council (MRC) has called for test cases to be taken to the Constitutional Court to establish the legal requirements for quarantine and compulsory treatment.
In an MRC policy brief published this year, before the XDR outbreak was announced, Weyer called for the enforced hospitalisation of high-risk MDR TB patients on the grounds that the risks to society outweigh individual rights. But she does not support forcible treatment of MDR TB patients, given the dangers and side effects associated with the drugs.
Edginton said quarantining was critical to curb the disease when some people would not or could not take the full course of drugs.
Even tougher issues are what to do with suspected MDR cases during the six weeks it can take for a laboratory to confirm the disease, and how to deal with MDR TB patients whom the treatment has failed to cure. Incarcerating the latter until they die — which could be years — would be ethically questionable and impractical.
Edginton also pointed out that the healthcare system had some responsibility for MDR and XDR. Poor follow-up and case management, unfriendly and rude healthcare workers, inconvenient clinic hours for those who work, problems facing patients in reaching accredited TB clinics and lack of education on the need to complete the course of drugs contributed to its transmission, as did social factors such as the stigma associated with TB and its links with HIV.
Willem Sturm, a dean at Durban’s Nelson Mandela Medical School who is involved in the KwaZulu-Natal research, said the rise of XDR and MDR TB stems from the low success rates in treating even normal TB, and the intersection of two separate killer epidemics: TB and HIV.
More than half of adult South Africans have latent TB and in KwaZulu-Natal, three-quarters of TB patients are also HIV-positive.