How We Treat TB Today
A Talk With Gavin Churchyard
Professor Gavin Churchyard is the director of the Aurum Institute for Health Research, which provides health care services to many mining companies in South Africa but is also an independent health research center conducting a number of important clinical trials, including the Thibela-TB trial of isoniazid preventive therapy (IPT) in 35,000 mine workers, funded by the CREATE consortium with support from the Bill & Melinda Gates Foundation, and a pivotal study of a new HIV vaccine sponsored by the U.S. National Institutes of Health and Merck & Co. Dr. Churchyard has been conducting research and providing health care to South African miners for over a decade and is a world-respected expert on TB. I spoke to him during a meeting held at Kwa Maritane, Pilanesberg, South Africa, from 18-20 September, involving researchers from Brazil, the U.K., the U.S., Zambia, and South Africa who are conducting three very large studies to better understand how to control HIV-associated TB infections.
Dr. Churchyard: The extent of multi-drug resistant (MDR), highly-drug resistant, and extensively drug resistant (XDR) TB in the mining industry is unknown at this time. Some of the MDR TB which we know exists in the mines is likely to be XDR TB -- we don't yet know how much. The overall rate of MDR in the mining industry is 2-3% (1% in people with first TB infection and 4% in TB retreatment cases). The industry needs to implement surveillance strategies to quantify the magnitude of the MDR/XDR epidemic, and strengthen and intensify infectious control policies at all levels.
Individuals should be urged to seek testing to know their HIV status, offered antiretrovirals early, and communities need intensified awareness and education about TB symptoms so they can seek out diagnosis and treatment for TB as early as possible.
The health system in the mines incorporates high-quality diagnostic and treatment facilities which can diagnose TB rapidly, detect whether it is drug-resistant, and apply the best treatment regimen which would be appropriate for the resistant strain, if MDR or XDR. However remember that 97% of TB cases are curable with six months of proven effective and safe combination therapy. TB can also be prevented with six to nine months of isoniazid (INH) preventive therapy (IPT), which has proved to work in many countries in over forty years of research and is effective among people with HIV.
It is particularly urgent for HIV-infected persons with TB symptoms to be rapidly diagnosed as the XDR strain rapidly kills people with HIV (within days).
Everyone must learn, understand, and implement effective infection control procedures including light, ventilation, identifying coughing patients and having special places for them in waiting rooms and clinics, expedited screening, educating health care workers, patients, community members, political leaders, and the media about how to prevent TB transmission, how to seek care for TB symptoms, how to diagnose, treat, and cure TB. By far most TB cases are sensitive and respond to therapy.
Individuals with TB including XDR-TB are human beings with human rights. We must treat all people with TB with respect, preserve their dignity, and save their lives. There is no role for stigma and discrimination in managing TB. By explaining the importance of adherence to TB treatment, we can help support individuals with the disease to achieve treatment success and save their lives.
Some individuals with XDR TB may be treated in single bed hospital rooms. They are not pariahs. Wearing a mask can prevent transmission even in the weeks when they may still be shedding TB bacteria by coughing. Regular TB drugs eliminate infectiousness after two weeks. There is a simple test (the sputum smear microscope acid-fast bacilli test) which can determine whether someone is still infectious. Most people stop being infectious after treatment is initiated. With MDR and XDR TB the time to loss of infectiousness is more variable. Treatment takes longer and involves more drugs, with greater side effects. However many cases of MDR TB can be cured if caught in time. XDR TB can be treated but it is not yet clear whether it can be cured without new drugs still in early phases of development. This terrible outbreak of XDR TB demonstrates how critical it is to assure access to high-quality TB services for all, and to accelerate and intensify research to discover new drugs to cure MDR and XDR TB.