HIV complicates fight against TB

Walter (not his real name) has spent four months of his young life confined to the children's ward at Sizwe Hospital in Johannesburg, South Africa. His growth has been stunted by a version of tuberculosis (TB) that is resistant to the most widely available drugs, and the three-year-old has another 14 months at the hospital ahead of him, taking a powerful combination of alternative medications. Walter caught a multidrug resistant (MDR) strain of TB from his mother, who is being treated in a different ward of the same hospital. He is also HIV positive - another legacy from his mother - which has made him more susceptible to MDR-TB, further complicating his treatment. Despite the lengthy stay at a hospital that specialises in MDR-TB cases, he still only stands a 50 percent chance of conquering the disease. According to Dr K P Manda, chief medical officer at Sizwe, cases of MDR-TB are on the rise, fuelled by the HIV/AIDS epidemic and the challenges of ensuring that TB patients complete a lengthy drug regimen. Currently only two percent of new TB patients in South Africa have multidrug resistant strains of the disease, but experts like Dr Karin Weyer, who heads the TB unit at South Africa's Medical Research Council, warn that unless governments in Africa act now, MDR-TB has the potential to develop into "an uncontrollable epidemic". TB is primarily an illness of the respiratory system, spread by coughing and sneezing, which kills about two million people across the globe each year. The disease is linked to poverty, with Africa accounting for a quarter of all notified TB cases worldwide. The strategy for treating TB, adopted by the World Health Organisation (WHO) 11 years ago, requires health workers to watch patients swallow their pills for at least the first two months of treatment. Directly Observed Treatment Short-course (DOTS) strategy, as it is known, demands that patients then be closely monitored to make sure they complete the entire six-month course of drugs. Overstretched Health Services The problem with this approach, noted Weyer, is that health systems in Africa are already over-burdened by the HIV/AIDS epidemic and lack the capacity to supervise the millions of individuals in need of TB treatment. The task often falls to unpaid, untrained community health workers, and even they are in short supply. In too many cases, patients simply stop taking their daily pill as soon as they feel well, giving the disease an opportunity to mutate and eventually return in a multidrug resistant form. Patients with MDR-TB generally need four months of treatment at a centre like Sizwe, followed by a further 14 to 18 months of monitored pill-taking. The cost of treating this type of TB is more than 100 times that of treating the original version, and has a much lower success rate. International relief agency Medecins Sans Frontieres (MSF) has been campaigning loudly in recent months for a radical rethink of the DOTS strategy that would take into account the realities of HIV and MDR-TB; MSF is also calling for more investment in the research and development of better diagnostic tests, and new drugs that would shorten treatment times and lessen the need for supervision. Weyer shares MSF's concerns but, in the absence of tried and tested alternatives, believes a more useful focus would be on improving the existing strategy. "It's the implementation of the DOTS strategy that's really a problem, and it relates back to limited capacity at the primary healthcare level," she told PlusNews. Walter is actually among the lucky few. Sizwe Hospital is the only referral centre in Gauteng Province for MDR-TB cases, and one of only a handful on the continent. For the duration of his stay he will receive the best possible care, a nutritious high-protein diet and pleasant living conditions, all at the state's expense. The colonial-era Sizwe complex is spread out over leafy grounds where patients are encouraged to spend much of their time seated outside on the shady verandahs, breathing fresh air. The problem, say both Manda and Weyer, is what happens to the majority of patients who leave the centre with up to 18 months of drug treatment still to complete. In many cases they return to a poor diet and unsanitary living conditions, while the clinics responsible for monitoring their continued treatment often lack the staff to do so. "They're over-worked and under-resourced, so patients disappear from treatment and then come back with multidrug resistance," said Weyer. Adapting DOTS It is estimated that only one in three TB patients in Africa complete their full drug course. In regions where conflict and political instability force people to flee their homes, the challenges of treatment have largely been considered insurmountable. Rather than risk MDR-TB developing, most governments and relief agencies make the decision not to treat TB at all under such conditions. The exception is MSF, which piloted several TB treatment centres in war-torn southern Sudan, with good results. The key to the Sudan programme's success, said its director, Dr Kees Keus, has been to adapt the DOTS strategy, so that it makes sense in the context of an insecure environment where the local population is also semi-nomadic. Patients are kept at treatment centres for four months instead of the usual two, during which time they receive extensive adherence counselling. They are given a three-month supply of drugs when they leave, but there is little or no possibility of being able to monitor them after that point. The adherence counselling, in addition to the use of a combination of four different drugs, is aimed at lowering the risk of MDR-TB cases. "If you have the choice between treatment and no treatment, you should look at alternatives," Keus explained. "I think you shouldn't use one regimen as the bible, but should look at the context and see what is possible, and sometimes you have to make a regimen that isn't as optimal as the WHO-recommended one." Part of that context in sub-Saharan Africa is the HIV/AIDS epidemic. The two diseases form a deadly combination, and many of the complications that bring TB patients to Sizwe are associated with HIV. Up to 75 percent of TB patients in Africa are HIV-positive, where TB is the most lethal HIV-related illness. Despite the fact that the two diseases so often go hand in hand, governments have been slow to implement more integrated treatment strategies. In many cases, patients still have to go to two separate clinics to seek treatment. One of the difficulties of combining treatment under one roof is the danger that the stigma attached to HIV will extend to TB. Joe Khoali, medical advisor for Gauteng Province's TB control programme, believes that fear of stigma is already hampering TB diagnosis and treatment. "People tend to associate TB with HIV," he noted. "TB used not to have a stigma, but now they don't come forward to be tested. In South Africa we get our cases very, very late and by that time they've infected a lot of people around them." Despite the obstacles, South Africa is one of the few countries on the continent taking steps towards greater integration of HIV and TB treatment. It is now policy that all TB patients be counselled to get tested for HIV, and that all those who test HIV positive be screened for TB. But policy does not always translate into practice, Weyer said. In theory, all MDR-TB patients automatically qualify for anti-AIDS drugs but, in reality, the country's 12 special MDR centres have yet to be accredited to distribute antiretrovirals (ARVs). Sizwe patients have to travel to Johannesburg General Hospital for ARV treatment, although hospital CEO, Elizma van Staden, said Sizwe would be able to prescribe antiretrovirals by next month. The DOTS strategy has been criticised for policing patients, rather than educating them to take responsibility for their own health, as is the case with AIDS patients about to begin ARV treatment. Making use of counsellors trained to educate AIDS patients about the importance of drug adherence is another plan yet to make it off the drawing board in South Africa. Currently, TB patients receive little or no adherence counselling. Relief workers, doctors and government administrators all tend to agree on one point: when it comes to treating TB more effectively, the bottom line is that the entire healthcare system should first be strengthened. National director for TB control in South Africa, Dr Lindiwe Mzusi, described it as "going back to basics", including the need for more laboratories to make diagnosis more accessible, and greater coordination with NGOs and community organisations to assist with adherence. "Healthcare infrastructures need to be improved to contain these problems," said Keus. "I don't think you can do this by just focusing on one or two diseases - you need a functioning primary healthcare system."