Fight against TB, HIV intensifies

 30/06/2011

By VIOLET MENGO

AS TUBERCULOUS (TB) and HIV continue to ravage Zambia and many other sub-Saharan countries, researchers at the Zambia AIDS Related TB Project (ZAMBART) are leading a study whose results will help establish whether a mix of community-level interventions can halt the spread of TB and HIV in Zambia.

TB is the biggest killer of people with HIV, particularly in sub-Saharan Africa. The scientific community is aware of the link between the two diseases but communities where many people are hardest hit by the HIV plus TB may be unaware of the link between the two.

Formed in 1989 following a collaboration between the University of Zambia's School of Medicine and the London School of Hygiene and Tropical Medicine in the United Kingdom, ZAMBART is working with learning institutions in Zambia and around the world with the aim of coming up with a new method of tackling the co-epidemics.

For example, ZAMBART is currently finalising its Zambia-South Africa TB and AIDS Reduction (ZAMSTAR) study.

The ZAMSTAR study is a seven-year (2004 - 2011) US$15 million study, seeking to test interventions that can limit the spread of TB at the community-level. The study is a randomised trial that took place in 24 communities - 16 in Zambia and eight in Western Cape of South Africa. This study, the largest ever of its kind, touched over 1.2 million people.

The ZAMSTAR study is funded by the Bill & Melinda Gates Foundation through the Consortium to Respond Effectively to the AIDS and TB Epidemics. TB is a bacterium that infects the lungs, and spreads between people living in over-crowed conditions. It is particularly a problem for people living in poverty, and for people infected with HIV.

In fact, TB is the leading cause of illness and death among people living with HIV and AIDS (PLWHA) in Zambia. About 70 percent of PLWHA are co-infected with TB and HIV, according to the World Health Organisation (WHO). Diagnosis depends mostly on a century-old approach of microscopy to look at smears of patients' sputum to identify the TB organisms visually, or through laboratory culture, which can take six to eight weeks.

For a period of three years (2006 - 2009), the ZAMSTAR study implemented a number of interventions at community level with the support of the District Health services.

The interventions included helping TB and HIV services work together (integration of TB and HIV service and care), finding more TB cases (enhanced TB case finding) and delivering TB and HIV care directly to households through a TB patient (household counselling).

In order to reach communities with messages on TB and HIV, the ZAMSTAR study utilised an array of different social mobilisation techniques. These included: drama performance, distribution of information, education and communication (IEC) materials, providing health talks within the community and at the clinic, going to schools and educating school children on TB and HIV with school quizzes, sport and health debate.

In each community team, ZAMSTAR members were embedded in the District Health Management Team and in the Ministry of Health facilities. Through the ZAMSTAR interventions, researchers are trying to measure how effective the interventions are at reducing the spread of TB and HIV at the community level.

"The ZAMSTAR has had a number of successes, it has been most rewarding to see, my greatest pleasure is to see that communities are much more aware about the link between HIV and TB and how it is important for them to seek prompt treatment from health centres," says Justin O'Brien.

ZAMBART Project Policy Advocacy and communication manager. The Zambian government through the Ministry of Health (MoH) also authorised ZAMBART to pilot Ionized Preventive Therapy (IPT) in all the communities where the ZAMSTAR study is being conducted.

IPT is given to individuals living with HIV but without TB to reduce their risk of developing TB. Past research has shown that IPT reduces incidence of TB by as much as 33 percent in those who take it.

In addition, IPT offers several key benefits which include: well tolerated with few side-effects, improves the quality of life of beneficiaries, leads to overall reduction of TB cases, reduces TB transmission within the family and the community and reduces the burden on the health care system.

ZAMBART installed four containerised laboratories within Zambia to process sputum samples and conducts extensive data collection training for its field teams.

These containerised TB laboratories, called ZamLab CTLs, were introduced in the country in an effort to conduct a large-scale TB prevalence survey in a less-developed country with a poor transportation network.

The use of these ZamLab CTLs in Zambia has proven so successful that labs are being ordered and constructed all over the world in countries such as Haiti, Kenya and Botswana. Treatment for TB involves drugs such as Rifampicin and Isoniazid, which takes six months to complete the treatment, and then six months of hospital visits to make sure the infection has been cleared. TB is curable when one finishes their treatment.

The Centre for Infectious Disease Research in Zambia (CIDRZ) is another non-governmental organisation which has been working with TB- related research in Zambia since 2008. One area of research focus is defining the best strategies for screening and treating patients infected with both HIV and TB. For example, CIDRZ recently completed an international study with AIDS Clinical Trials Groups (ACTG) on the best time to start antiretroviral drugs (ART) in patients with both TB and HIV.

All the TB studies we do at CIDRZ are relevant to Zambia and other resource- limited settings," CIDRZ Medical Director Dr Stewart Reid says. He says CIDRZ works closely with the Ministry of Health and the UNZA Biomedical Research Ethics Committee and external independent monitors to ensure that all ethical issues in research are adhered to.

The ACTG treatment study found that for patients with both TB and HIV, it is important to start ART early, especially in patients with advanced HIV disease. These results were shared with Dr Nathan Kapata, manager of the National Tuberculosis and Leprosy Programme at the Ministry of Health.

Sharing of information about research results between Zambia-based researchers and the MoH ensures that proven evidence identified through ethical research may be incorporated into policy so that Zambians benefit from the research done in the country. CIDRZ also works closely with the MoH in improving TB diagnosis in district clinics.

Dr Nzali Kancheya, head of CIDRZ TB Department, says there are many challenges in TB screening in HIV-positive patients. She explains that it is difficult to find the TB germ when the standard sputum smear microscopy is done. Up to 50 percent positive patients may be missed if smear alone is used.

As a result, CIDRZ is trying to investigate better ways of diagnosing TB in HIV-positive patients. "We are looking for more accurate, shorter and easier ways of diagnosing TB, Dr Kancheya says. One way of doing this is with a new instrument called Xpert MTB/RIP which has recently been approved by World Health Organisation (WHO).

It provides accurate results in less than 90 minutes and is more sensitive than older methods for diagnosing TB especially in HIV- infected individuals.

In addition to diagnosing TB, it can be used for rapid detection for multi-drug resistant TB (MDR-TB) and is recommended for use worldwide at district and sub-district level as a "point of care" diagnostic tool. CIDRZ along with the MoH is planning clinical trials of this promising tool in Zambia this year. With renewed interest in more research and funding, the fight against TB has moved a notch higher and may soon be won.

ENDS