TUBERCULOSIS RESEARCH DIVISION
Fuelled by HIV, tuberculosis (TB) notification rates in areas around Cape Town are among the highest in the world. TB is the most common opportunistic infection and, despite the country’s large antiretroviral treatment (ART) programme, remains a major cause of death among individuals with AIDS.
The DTHF is actively engaged in research at laboratory, clinical, and public health levels to increase our understanding of this epidemic and to seek solutions to this overwhelming health problem facing South Africans.
Epidemiological Studies of TB
Ongoing monitoring of TB notification rates in Masiphumelele (since 1996), has enabled us to describe the impact of the escalating HIV epidemic and subsequently the roll-out of the ART programme on TB burden of disease in this community.
Over ten years of molecular epidemiological data including DNA fingerprinting of all TB sputum strains have provided insights into transmission patterns in the HIV infected and uninfected populations. In addition tuberculin skin test surveys in the community schools have provided understanding of high TB infection rates in the community.
In collaboration with the UCT Department of Engineering we have developed an innovative approach to the study of TB transmission, using measurements of individual-based environmental CO2 monitoring to determine rebreathed litres of air as a surrogate measure of risk of TB infection.
TB and ART Cohort Studies
The Gugulethu Hannan Crusaid ART clinic has been the primary focus of our work addressing key issues related to the extremely high burden of TB within ART clinics in Cape Town. This has included identifying risk factors for TB in patients receiving ART, the impact of ART on TB incidence, and the impact of TB within the programme on mortality and outcomes of ART. These studies have also explored the underlying mechanisms for the high rate of TB during ART.
Studies on diagnosis of TB have also been performed, including examining strategies to improve diagnosis of TB at ART programme entry, and operational research of new diagnostic tools, including the use of the GeneXpert machine and LAM.
The DTHC was awarded one of the high profile, MRC flagship projects aimed at addressing South Africa’s key health problems. The project, Tuberculosis Transmission; Host, Bacterium and Environment is very interdisciplinary in scope with Professor Robin Wood heading up the team with collaborators Prof Valerie Mizrahi, Prof Jonathan Blackburn, A/Prof Nicola Mulder, A/Prof Thomas Scriba, Dr Carl Morrow, Dr Digby Warner, Dr Sara Suliman, Mr Samuel Ginsberg and Prof Linda-Gail Bekker bringing a strikingly diverse range of skill sets together to tackle a problem that has challenged scientists for a hundred years. The project aims to systematically address bacterial, host and environmental factors contributing to TB transmission in a high-burdened target community using an array of innovative new tools.
Integration of TB and HIV services
In partnership with Dr Richard Kaplan of the DTHF treatment division we have provided support for the initiation of an integrated antiretroviral and TB clinic with Cape Town City Health Department and the development of an integrated TB and HIV adherence framework for patients on TB treatment and ART. We are also involved in an operation research project evaluating the impact of an integrated TB and HIV/ART program on TB treatment outcomes.
Ongoing epidemiological studies
Dr Sabine Hermans has joined the Foundation from the Netherlands for a three year post-doctoral fellowship funded by the European Union. She is investigating HIV and TB epidemiology in the Cape Metropolitan area with the view of developing a model of TB disease in Cape Town.
In addition, Dr Middelkoop continues the population molecular epidemiological studies in Masiphumelele, including GIS-based analysis to determine possible high risk locations for TB transmission and whole genome sequencing analysis of transmission clusters.
- Other studies
- TB transmission risk studies, utilizing C02 measurements, among adolescents
- A retrospective study of the influence of HIV-co-infection on TB treatment outcomes in the Cape Town primary health care TB services
- A cross-sectional survey to assess determinants of TST status among patients receiving ART
- Systematic screening study for HIV-associated tuberculosis in patients admitted to a local District Hospital, utilizing different TB diagnostics
- Future studies:
- Adolescent TB infection cohort
- Collaboration with basic scientists at the Institute of Infectious Disease and Molecular Medicine, to understand the mycobacterial and immunological factors associated with Mtb strain success in a high burden community over time