In-depth: TB and HIV: Deadly allies

SOUTH AFRICA: Reducing TB a matter of life and death

Photo: Gary Hampton/World Lung Foundation

Waiting for TB treatment

durban, 1 April 2009 (PlusNews) - Several years ago, the World Health Organization (WHO) identified the three most important ways of reducing the risk of tuberculosis (TB) in people living with HIV, who are highly susceptible to the airborne disease.

The strategy, called the “3 I’s”, includes "Improving TB infection control", "Intensifying efforts to diagnose TB cases", and "Isoniazid for six months" - giving HIV-infected patients six months of Isoniazid, a first-line TB drug, as a preventive therapy.

The approach was widely recognized as effective and feasible, and incorporated into a number of national TB policies, yet TB – the most common and life-threatening opportunistic infection in people living with HIV – claimed the lives of an estimated 230,000 HIV-positive people in 2008, according to WHO.

South Africa, which accounts for a third of all patients co-infected with HIV and TB in Africa, is among the countries that adopted the 3 I's, but presentations to a symposium on 31 March at the 4th South African AIDS Conference in the east-coast city of Durban, said implementation had been virtually non-existent.

“Let’s just do it!” several speakers urged in an effort to galvanize the support of attendees, many of whom work in the health sector, to translate TB reduction policies into action.

Trying to slow the spread

Studies have found that a lack of infection control – the first “I”, and perhaps the most fundamental in preventing new TB cases – was largely responsible for the outbreak of extensively drug-resistant TB (XDR-TB) in South Africa’s KwaZulu-Natal Province in 2006.

Lesley Odendal, an infection control coordinator with Médecins Sans Frontières, the international medical humanitarian organization, said the majority of drug-resistant TB cases in South Africa were the result of primary infection rather than patients not adhering to first-line TB drugs - “the clearest illustration we’re failing in infection control”.

Basic interventions, such as ensuring an adequate supply of masks to healthcare workers and patients, educating communities about how to reduce the spread of TB, and supporting individual healthcare facilities to design their own infection control plans, were lacking. “These are simple measures and it’s despicable that we aren’t implementing them.”

Odendal also noted that a national infection control policy had been in draft form since 2007.

Catching cases early

The second “I”’, intensified case finding, means regularly screening people infected with HIV, and other groups at high risk of TB, such as healthcare workers and miners, rather than waiting for patients to present with symptoms.

“Passive case-finding is not effective,” said Dr Celine Gounder of Johns Hopkins University, in Baltimore, in the US. “By the time a patient is symptomatic they’re infecting others, and mortality rates are high.”

Gounder cited a Cape Town study which found that only about one-third of HIV-positive patients with TB were diagnosed.

Dr Salome Charalambous of the Aurum Institute, a health research NGO, noted that HIV-positive patients were usually only screened for TB before starting antiretroviral (ARV) treatment, but remained at a higher risk of TB even after starting anti-AIDS medication. “There needs to be continuous screening,” she said.

Sputum tests, the quickest and cheapest TB screening method, are less effective in HIV-positive patients and have to be combined with other approaches, such as chest x-rays and symptom check-lists, but a study in 24 communities in South Africa and Zambia has shown that TB case detection can be dramatically increased by educating communities about the benefits of regular TB screening and ensuring easy access to it.

Using available methods

Providing Isoniazid Preventive Therapy (IPT) to people living with HIV, the final “I”, can lower their risk of contracting TB by 33 percent, but in 2008 less than 7,000 HIV-positive people in South Africa received a six-month course of the drug.

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With the exception of Botswana, other countries are not doing much better. According to the latest global TB control report by WHO, only about 29,000 people were started on IPT worldwide in 2007. Rolling out IPT depends on improved TB screening, as patients can only be given this treatment if they do not have active TB.

WHO also recommends TB skin tests, which can determine whether a patient has latent TB infection, but speakers at the symposium were in favour of removing this requirement from South Africa’s guidelines, as the tests are widely considered to be unreliable and a further barrier to making IPT widely available.

Concerns about adherence, drug resistance, the difficulty of ruling out active TB, and the cost of IPT have all been given as reasons for not providing it, but Dr Vincent Tihon, a TB-HIV advisor to South Africa’s department of health, dismissed these as excuses.

He said there was no evidence that IPT promoted drug-resistance, and the intervention was much cheaper than treating TB; political commitment to roll out IPT more widely in South Africa had increased in recent months and revised IPT guidelines were expected to be approved by June.

“IPT is feasible and cost-effective,” said Prof Harry Hausler of the University of Western Cape. “Failure to provide [it] is a human rights violation and will worsen the epidemic; let’s just do it.”

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TB and HIV: Deadly allies
March 2009

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