/ 25 March 2005

Tackling the twin menaces of HIV and TB

HIV has completely changed the face of South Africa’s tuberculosis epidemic, with tuberculosis (TB) patients today being young, sicker and often with unusual presentations of TB, according to health experts.

”Ten years ago, the majority of TB patients were old or malnourished. But now the wards are full of young people who are dying. This can only be explained by the link between TB and the HIV epidemic,” says Prof Salim Abdool Karim, director of the Centre for the Aids Programme of Research in South Africa (Caprisa).

”Most of us, in South Africa, are exposed to TB, but our bodies’ immune systems are able to keep it in check. This is why, without HIV attacking the immune system, TB was a disease mainly of the elderly and very young.”

In addition, TB usually infects the lungs but there has been a marked increase in unusual presentations of TB both in the lungs as well as outside of the lungs (extrapulmonary), says Dr Nesri Padayatchi, who heads Caprisa’s TB research.

”Extrapulmonary TB is more common in people who are HIV-positive, perhaps because their immunity is compromised and the bacteria can be more widely disseminated in the body,” says Padayatchi, who until recently headed King George V hospital, KwaZulu-Natal’s TB referral centre.

In 1996, only 6% of TB cases were extrapulmonary but, by 2002, this had more than doubled to 15%, according to the SA Health Review.

Extrapulmonary cases include TB meningitis, TB in the bone, lymph nodes, abdomen and the covering of the heart (pericardial).

”About 79% of people with pericardial TB have been found to be HIV-positive,” says Padayatchi.

Concerned by the close association of TB and HIV, Caprisa is pioneering an innovative approach to see whether TB and Aids care can be integrated. The idea is to recruit patients for antiretroviral (ARV) therapy before their immune system is so weak that their recovery is difficult.

New clinic

The Caprisa eThekwini TB/HIV clinic started operating in late November, adjoining Durban’s Prince Cyril Zulu clinic, one of the country’s biggest TB clinics.

Situated in the city’s crowded transport hub, Warwick Triangle, up to 18 000 patients pass through the Prince Cyril Zulu clinic every month.

About three-quarters of the clinic’s TB patients are also HIV-positive. By 2002, 55% of TB patients nationally were living with HIV.

The clinic is a joint venture between Caprisa, the University of KwaZulu-Natal and the eThekwini municipality and was built with money from the United states President’s Emergency Plan for Aids Relief (Pepfar). It is already seeing about 60 patients a day who are referred from Prince Cyril Zulu TB clinic, next door.

The spacious clinic, which is partly run with money from the Global Fund to Fight Aids, TB and Malaria, employs four doctors, four counsellors, two nurses and two health educators.

Patients are offered HIV counselling and testing, adherence support training and CD4 and viral load tests to see whether they need to start ARVs.

”Most patients are in their early 20s to 30s, predominantly women and unemployed,” says the clinic’s Dr Arthi Singh. ”Their CD4 counts tend to be low. Some have known for a while that they have HIV and all want treatment. So far there has been good adherence to the anti-retroviral drugs.”

Singh added that staff appreciate that the clinic is airy and well ventilated to reduce the risk of TB transmission within the clinic.

The clinic’s Aids treatment activities are based on the belief that ”the best approach [for introducing anti-retroviral therapy] is to start with TB and sexually transmitted infections clinics”, says Abdool Karim.

”South Africa has spent years building TB facilities, including laboratory support. TB clinics are also grappling with the problem of adherence and the two infections often go together.”

In addition, offering HIV tests to TB patients is a better use of resources than going via general or antenatal clinics, as well more than half of the TB patients have HIV as opposed to about a third of pregnant women.

Combination of drugs

Within months, the clinic is to begin a study into whether people co-infected with TB and HIV can take TB drugs and ARVs at the same time.

”Highly active anti-retroviral therapy is the best way to stop recurrent TB,” says Abdool Karim. ”But one of the drugs essential for TB treatment, Rifampin, weakens the efficacy of two of the three classes of anti-retroviral drugs. You can up the dose of the anti-retroviral drugs to offset this problem but that will increase the side-effects.”

In addition, combined TB and HIV treatment means a patient would be taking seven drugs at a time and this could have ”any one of a number of side-effects”, he says.

”That’s why doctors are so reluctant to give TB and HIV drugs at the same time,” says Abdool Karim. ”But research shows that mortality in people infected with TB and HIV tends to peak at around three months of TB treatment, so we are trying to understand whether we can save lives by treating people at the same time”.

The study — called Start (Starting TB and Anti-Retroviral Treatment) — has taken two years to get through all the ethical and procedural hoops, and is finally ready to begin in May.

About 700 patients with TB who also need ARVs will be monitored over two years. Half will complete their TB treatment first before being given ARVs and the other half with get both drug treatments at the same time.

Patients with CD4 counts of less than 50 are likely to be excluded from the study, as it may not be ethical to withhold their ARV treatment for six months.

”Our goal is to try to treat thousands of people at the clinic and to collect as much information as possible because we simply do not know many of the answers about how best to treat TB and HIV yet,” says Abdool Karim. — Health-e