HIV Control in Sub-Saharan Africa research group
Head of Group: Dr Simon Gregson
HIV prevalence levels and AIDS mortality remain extremely high in many countries in sub-Saharan African. In our multi-disciplinary research group we use a combination of empirical and mathematical modelling methods to develop understanding of the population impact of alternative control strategies in the context of the temporal dynamics of HIV epidemics.
Current Research Group Members:
- Dr Ben Lopman (Post-doctoral research fellow)
- Ms Constance Nyamukapa MSc (Research associate and graduate student)
- Mr Sabada Dube MPH (Research assistant and graduate student)
- Ms Helen Owen MSc (Research assistant and graduate student)
- Mr Timothy Hallett MSc (Research assistant and graduate student)
- Dr Boshishi Mohlala MD (Wellcome Trust Research Training Fellow)
- Ms Ide Cremin MSc (Graduate student)
- Ms Laura Robertson MSc (Graduate student)
Research Topics:
- HIV and Behavioural Surveillance
- Individual and Population-Level Determinants of HIV Transmission
- Socio-Demographic Impact of HIV/AIDS in sub-Saharan Africa
- Empirical Evaluation of HIV Control Interventions in Zimbabwe and South Africa
- Mathematical Modelling of HIV Control Interventions
HIV and Behavioural Surveillance
Tracking trends in the spread of HIV and associated behaviours is an essential pre-requisite for assessing the effectiveness of prevention and control programmes. Through the establishment (in 1998) and follow-up of a general population cohort of more than 10,000 adults and parallel surveillance of women attending local antenatal clinics, under the auspices of the Manicaland HIV/STD Prevention Project, we and our partners from the Biomedical Research and Training Institute in Harare are measuring trends in the epidemic in eastern Zimbabwe and evaluating the extent and nature of and methods for correcting bias in data collecetd using alternative surveillance methods. Results from this researchj are used by the UNAIDS Reference Group on Estimates, Modelling and Projections for which the Department of Infectious Disease Epidemiology provides the secretariat.
| People | Simon Gregson, Constance Nyamukapa, Ben Lopman, Tim Hallett |
| Collaborators (Imperial) | Geoff Garnett, Peter White |
| Collaborators (External) | Steven Chandiwana (BRTI and University of Witswatersrand), Peter Mason (BRTI), Basia Zaba (LSHTM - ALPHA Network) |
Links:
- Manicaland HIV/STD Prevention Project
- Biomedical Research and Training Institute
- UNAIDS Reference Group on Estimates, Modelling and Projections
- ALPHA Network
Current and Recent Research Projects:
- Description and attribution of trends in the HIV epidemic in Zimbabwe
- Development and evaluation of methods for estimating HIV incidence from cross-sectional survey data
- Development and evaluation of informal confidential voting interview methods for reducing social desirability bias in surveillance data on sexual behaviour
Individual and Population-Level Determinants of HIV Transmission
The nature and significance of socio-economic, biomedical and behavioural factors in HIV transmission can differ between populations and by stage of epidemic within the same population. Factors which are important at teh individual level are sometimes unimportant at the population level. We use empirical data from longitudinal population-based surveys in Zimbabwe (Manicaland HIV/STD Prevention Project) and mathematical models to improve understanding of the importance of different risk factors.
| People | Ben Lopman, Tim Hallett, Simon Gregson |
| Collaborators (External) | Steven Chandiwana (BRTI and University of Witswatersrand), Peter Mason (BRTI), Catherine Campbell (LSE) |
Links:
Current and Recent Research Projects:
- Evaluation of the proximate determinants framework as a theoretical model for explaining differences in HIV transmission between populations
- Evaluation of alternative methods for measuring socio-economic status in sub-Saharan African populations and measurement of the effect of poverty in HIV transmission
- Assessment of the significance of age-differences between sexual partnershops and age at first sex as determinants of HIV infection at the individual and population levels
- Assessment of the role of social capital in promoting successful avoidance of HIV infection
Socio-Demographic Impact of HIV/AIDS in sub-Saharan Africa
Most international estimates of the demographic impact of HIV/AIDS continue to be derived using mathematical models. Empirical data are therefore needed to parameterise and validate these models. The research group contributes to the development of the models used for assessing demographic impact both directly and through the collection and analysis of data from primary and secondary sources. In addition, we are developing theoretical frameworks aimed at improving understanding of aspects of the social impact of HIV-associated mortality.
| People | Simon Gregson, Ben Lopman, Constance Nyamukapa, Helen Owen |
| Collaborators (Imperial) | Geoff Garnett, Roy Anderson, Lesley Drake (Partnership for Child Development), Michael Beasley |
| Collaborators (External) | Phyllis Mushati (BRTI), Mainford Wambe (BRTI), Matthew Jukes (Harvard), Arjan Gjonca (LSE) |
Links:
Current and Recent Research Projects:
- Demographic impact of HIV/AIDS in Zimbabwe
- Development of verbal autopsy methods for estimating AIDS mortality
- Psychosocial effects of AIDS-associated orphanhood
- Consequences of orphanhood for children's health and nutrition
- Impact of HIV-associated mortality on househol viability and survival
Empirical Evaluation of HIV Control Interventions in Zimbabwe and South Africa
Many different approaches are being applied within countries in sub-Saharan Africa to combat the spread and impact of HIV and AIDS, there is still only very limited scientific evidence for the effectiveness of these approached in reducing the rate of new HIV infections. With our partners in Zimbawe, we have conducted one of the very small number of randomised controlled trials of HIV prevention interventions and are collecting longitudinal data on the coverage, parterns of uptake and effectiveness of alternative methods of prevention. We are also collecting longitudinal data on trends in uptake of antiretroviral therapy and the impact on survival at the population level.
| People | Simon Gregson, Constance Nyamukapa, Boshishi Mohlala, Ben Lopman, Ide Cremin, Laura Robertson |
| Collaborators (Imperial) | Geoff Garnett, Roy Anderson |
| Collaborators (External) | Catherine Campbell (LSE), Lorraine Sherr (UCL), Zivai Mupambireyi (BRTI), Peter Mason (BRTI), Steven Chandiwana (BRTI), Charles Mangongera (BRTI), Spiwe Papaya & Jephias Mundondo (Family AIDS Caring Trust, Mutare Zimbabwe) |
Current and Recent Research Projects:
- Community-randomised trial of peer education, condom distribution and syndromic management of STIs
- Longitudinal studies on the impact of voluntary conselling and testing on sexual behaviour and incidence of HIV infection
- Trends in uptake of antiretroviral therapy for HIV/AIDS and impact on mortality
- Malre involvement in preventionl of mother-to-child transmission in South Africa
- Use of conditional cash transfers to improve the well-being and development of children orphaned or made vulnerable by HIV/AIDS
Mathematical Modelling of HIV Control Interventions
Mathematical models can be used to guide the design and evaluation of different HIV prevention and control strategies. Through collaborations with other researchers in the Department of Infectious Disease Epidemiology and Imperial Colelge London and a cooperative agreement with the United States Centers for Disease Control and Prevention in Zimbabwe, members of the research group contribute to the development and application of these models.
| People | Tim Hallett, Sabada Dube, Simon Gregson |
| Collaborators (Imperial) | Geoff Garnett, Marie-Claude Boily |
| Collaborators (External) | Stacie Greby (CDC), Owen Mugurungi (Zimbabwe Ministry of Health) |
Current and Recent Research Projects:
- Evaluation of the impact of alternative prevention of mother-to-child transmission strategies on infant and early childhool mortality
- Interpretation of results from community-randomised controlled trials of HIV prevention interventions
- Optimisation of the population impact of voluntary counselling and testing
- Optimisation of the population impact of antiretroviral treatment of HIV/AIDS
- HIV prevention from a life-course perspective
Major Funders
The Wellcome Trust, US Centers for Disease Control and Prevention, The World Bank, The Medical Research Council, UNICEF, World Health Organisation
