Scientists are combining forces to tackle the deadly duo of TB and HIV
TB and HIV are, separately, two of the deadliest infections in the world. They kill around 3 million people every year. Combined, they are even more dangerous. Tackling the problem of HIV and TB co-infection presents both diagnostic and therapeutic challenges.
That’s why a new US$79-million centre, the Africa Health Research Institute, has been established in KwaZulu-Natal, South Africa. It will combine the efforts of two leading research organisations – the Africa Centre for Population Health and the KwaZulu-Natal Research Institute for TB-HIV (K-RITH). Incoming Africa Health Research Institute Director Professor Deenan Pillay explains the importance of this new research venture to KwaZulu-Natal, South Africa and the world.
Why is HIV and TB co-infection a challenge?
HIV and TB form a lethal combination, each speeding the other’s progress. TB is the leading cause of death among people living with HIV. It accounts for one in four HIV-related deaths. There are huge challenges in accurately diagnosing TB in people living with HIV, and then properly treating the co-infections.
The drugs that are used to treat TB must be taken for at least six months. Patients with drug resistant strains are sometimes treated for longer than two years, and have to use drugs which are more toxic. Anti-TB drugs may interact badly with antiretroviral drugs and both TB drugs and antiretrovirals have side effects, which means people often don’t adhere to their treatment regimes.
What are the co-infection rates in South Africa and how do they compare to the rest of the world?
Despite advances in antiretroviral therapy and talk of the ‘end of Aids’, HIV and HIV-related TB remain devastating diseases.
According to the World Health Organisation at least one-third of the 37 million people living with HIV worldwide are infected with latent, or inactive, TB. Globally, people living with HIV are 26 times more likely to develop active TB than those without HIV.
South Africa is the epicentre of HIV and TB co-infection. Of the 22 high burden TB countries the World Health Organisation lists, South Africa is ranked third. And more than 70% of patients with TB in South Africa are also HIV infected. TB is among the leading causes of death in the country.
KwaZulu-Natal (KZN), a province on the east coast of South Africa, has the highest rates of HIV and TB in the country. It also has one of the highest prevalence rates of TB globally. The largest outbreak of extensively drug resistant TB (XDR-TB) in history occurred in the province in 2006, while uMkhanyakude district, the area of northern KZN where the Africa Centre is based, has the highest prevalence of drug resistant TB in the country.
What prompted the centre and how will it actively help target co-infection?
The Africa Health Research Institute will use an interdisciplinary approach to fight HIV and TB, bringing together leading researchers from different fields. The Africa Centre, a population studies research centre, has existed since 1999. It has 16 years of detailed population data from more than 100 000 participants, and has been at the forefront of describing the development of the HIV epidemic and the positive impact that HIV treatment has had, both in terms of reducing the number of new infections and reducing mortality.
K-RITH was formed in 2009 in response to the devastating outbreak of XDR-TB in KZN. It is focused on the basic science of TB and HIV biology and pathology and has world-class laboratory facilities, including Biosafety Level 3 labs, which allows scientists to safely work with TB.
Bringing the two together links population and lab research to create an interdisciplinary “population to laboratory – and back to population” approach to addressing the TB and HIV co-epidemic. This is the first institute of its kind in the world where the highest class of lab research can be applied to such large population longitudinal surveillance.
In the past the Africa Centre has been able to describe the changes in the rates of new HIV infections and how that has affected the population. The Africa Health Research Institute can now look at why there are changes and can develop tools to do trials on that population. We are moving from observing, to doing something about it.
What are your targets?
The Africa Health Research Institute’s goals include providing the research to significantly reduce new HIV infections and new TB infections – based on developing optimal drugs, vaccines and trials of interventions and research of on-the-ground impact.
It is an important component of the South African effort to fight HIV and TB. The prevalence of infection is so high that we are in a good position to do the research and apply the findings not just to sub-Saharan Africa, but to areas across the world where HIV and TB is less prevalent but still a challenge.
The institute will also help develop the next generation of African scientists.