Home-based tuberculosis (TB) education and testing reduced community TB prevalence by about 20 percent, according to findings of a large, two-country study released at the International Lung Health Conference in Lille, France.
Conducted among almost 963,000 people in Zambia and South Africa, the ZAMSTAR study rolled out household education and TB testing to some communities while others received enhanced TB case detection, which included activities such as community dramas to raise TB awareness.
Some communities received both during the three-year trial that ended in 2009. While enhanced TB case detection had no effect on new cases of TB or TB prevalence, household interventions reduced prevalence and reduced the risk of contracting TB among children in targeted communities by half.
“In the era of HIV, this is the first community-randomized trial of a public health intervention to be shown to have an impact on the epidemiology of TB at community level,” said Peter Godfrey-Faussett, one of three ZAMSTAR principal investigators and professor of infectious diseases and international health at the London School of Hygiene and Tropical Medicine.
The study found that awareness-raising prompted more people to test for TB, which was conducted at clinics that fast-tracked TB screening and sputum collection or at community collection points that were no more than 30 minutes walk from patients’ homes. ZAMSTAR attempted to diagnose these patients in about 48 hours, although this was possible in only about a third of all sputum samples – some of which had to be transported to laboratories up to 800km away despite the implementation of several container labs in Zambia.
Participants who received household TB education were also offered family or couples HIV counselling and testing. While the trial was not able to offer home-based HIV testing, about two-thirds of those offered voluntary HIV testing did so at the nearest clinic. As a result, 4,000 patients started antiretroviral (ARV) treatment.
People living with HIV comprise about 10 percent of the world’s TB cases. In high-burden countries such as South Africa and Zambia, about 60 percent of TB patients are co-infected with HIV.
With increasing recognition of the role of diabetes – which suppresses the immune system and increases TB risk – in TB infection, households were also offered blood sugar tests.
From research to policy
While the trial cost US$27 million, the interventions it piloted cost about $0.80 per patient; however, the cost-effectiveness of household outreach has not yet been calculated.
This will be of particular interest not only to national policy-makers but also donors, who continue to tighten purse strings amid a global economic downturn.
“I think the results show unequivocally that we do need to take TB services out of the clinic,” said Yogan Pillay, deputy director-general for HIV/AIDS, TB and maternal, child and women’s health for South Africa’s Department of Health. “TB lives in communities and in households. We need to find people and diagnose and treat them [there] or we will have… multidrug-resistant TB [MDR-TB].”
MDR-TB is resistant to both the most powerful drugs used to treat active TB, rifampicin and isoniazid. It can be transmitted or can develop when patients fail to complete previous courses of TB medication.
However, Pillay voiced concern that findings from the ZAMSTAR study, which was conducted in South Africa’s Western Cape Province, may not be generalizable to the rest of the country. The Western Cape remains a high TB burden province, but with better-than-average healthcare provision, also has higher TB cure rates than many other provinces.
The study found an extremely high TB prevalence among its South Africa sites, with about 2,320 TB cases for every 100,000 adults. ZAMSTAR also found a high burden in its Zambian sites, with about 540 cases per 100,000 adults.
At the time of the study, only South Africa had national guidelines to provide TB contacts and high-risk groups such as HIV patients with isoniazid preventative TB therapy (IPT). But uptake remained low at the time of the ZAMSTAR study, according to Helen Ayles, project coordinator for Zambia AIDS-Related TB Project [ZAMBART], a local NGO that took part in the ZAMSTAR study.
Zambia does not provide IPT to at-risk patients as government policy, but the ZAMSTAR study was allowed to offer this to patients and proved that providing IPT was feasible – a result that may lead to a change in government policy, according to Nathan Kapata, national TB programme manager with Zambia’s Ministry of Health.
“We can learn that implementing IPT is possible,” he told IRIN/PlusNews. “It gives me great strength that we can actually implement [it].”