Assessing the impact of HIV-1 in the black Caribbean community in south London

Until recently, there had been a striking absence of research on the behavioural and epidemiological aspects of HIV in the UK black Caribbean community. The LIVITY study was established to answer questions on HIV acquisition and risk behaviours and found evidence of high risk sexual behaviours present among both HIV-positive and -negative black Caribbean participants, frequent sexual contact in the Caribbean or with recent migrants from the Caribbean in the UK, highlighting a potential overlap with the HIV epidemic in the Caribbean.

The main aim of this study is to further characterise HIV within the black Caribbean community by integrating results from questionnaires and interviews in order to increase understanding of the reasons behind behaviours. Data can also be used to parameterise mathematical models of HIV transmission to explore the importance of different risk behaviours and the geographic movement between the UK and Caribbean. In addition, they will help to identify and evaluate interventions, aimed to reduce risky sexual behaviours or by treatment of HIV with antiretroviral therapy, to prevent further spread of HIV within this community.

The potential for an HIV epidemic in the UK black Caribbean community (BCC) is of major public health concern. The LIVITY study, established 2004, was the first comprehensive study of HIV-1 infection in the BCC in south London. Key results were the: high proportion of HIV acquisition in the UK; overlap with the HIV epidemic in the Caribbean through sexual contact in the Caribbean and/or with recent arrivals from the Caribbean; high proportion of heterosexuals reporting risky sexual behaviours including sexual debut <16 years old, recent concurrent partnerships, and high number of lifetime sexual partners. Qualitative interviews highlighted the profound impact of stigma on sexual behaviours, disclosure and coping strategies.

The principal aim of this project is to build upon these initial findings from the LIVITY study, and to utilise additional datasets and several methodological approaches to fully characterise the current status, likely future course and impact of HIV in the BCC in south London and UK. A key hypothesis is that the HIV epidemic among the BCC is driven by a core group of HIV-positive Caribbeans with risky sexual behaviours, and sexual contact with recent HIV-positive BC migrants.

The main data sources to be used are: (i)LIVITY: clinic-based quantitative and qualitative study of BC HIV-positive patients and STD clinic attendees: (ii)Caribbean sexual Health in south-east London (CHIL): community-based quantitative and qualitative study of sexual behaviour, knowledge and attitudes of recent BC UK migrants; (iii) NATSAL 2000: population study of sexual attitudes and behaviours.

Specific objectives are to: (i)analyse and integrate LIVITY and CHIL data to develop an enriched dataset; (ii)undertake a mixed-methods analysis through the construction and analysis of a metamatrix, containing full information from all data sources on sexual behaviours, HIV disclosure and support-seeking behaviours, providing a description of current behaviours AND explanations/settings for them; (ii)estimate HIV prevalence in the BCC in the UK through Bayesian statistical projections using several national datasets; (iv)Use data from (i)-(iii) to develop mathematical models to further understand and predict the likely pattern of ongoing HIV transmission in this population. Modelling work will build on the existing repertoire of deterministic-compartmental models, pair-wise models and individual-based simulations for HIV transmission, and used to explore the importance of high-risk groups, movement of people between the Caribbean and the UK and partnership dynamics in the propagation of BC HIV epidemic. In addition, the impact of strategies including STI treatment and partner notification/screening will be investigated.