20th International AIDS Conference - Melbourne, Australia


THAC0303 - Oral Abstract Session

Estimating the potential impact and efficiency of pre-exposure prophylaxis for female sex workers and men who have sex with men in Bangalore, southern India

Presented by Kate Margaret Mitchell (United Kingdom).

K.M. Mitchell1, F. Terris-Prestholt1, H.J. Prudden1, B.M. Ramesh2,3, R. Washington2,4, S. Isac2, S. Rajaram5, P. Vickerman6

1London School of Hygiene and Tropical Medicine, Global Health and Development, London, United Kingdom, 2Karnataka Health Promotion Trust, Bangalore, India, 3University of Manitoba, Winnipeg, Canada, 4St John's Research Institute, Bangalore, India, 5CHARME-India Project, Bangalore, India, 6University of Bristol, Bristol, United Kingdom

Background: In Bangalore, HIV infection is concentrated amongst men who have sex with men (MSM), female sex workers (FSWs) and their commercial clients. Intervention programmes have increased condom use amongst these populations. We estimated the additional impact of targeted pre-exposure prophylaxis (PrEP) for high-risk MSM (HR-MSM) and/or FSWs.
Methods: A deterministic model of HIV transmission between MSM, FSWs, commercial clients of FSWs and the low-risk general population was parameterised using Bangalore data. The model was fitted to HIV prevalence data for MSM, FSW and clients, and to ART coverage data for Bangalore from multiple time points, and was used to project the impact of PrEP targeted to FSW, HR-MSM or both groups, for different PrEP coverage and efficacy assumptions. Impact was estimated in terms of infections averted (IA) and life-years gained (LYG), and efficiency was estimated as years of PrEP per LYG.
Results: Over 10 years, the model predicted that a PrEP intervention with 40% coverage of the target population and 60% efficacy could avert over a fifth of new infections amongst the targeted population (FSW or HR-MSM), and 2-3% of new infections in the whole population. Impact increased with higher efficacy and coverage. Targeting FSW had a greater population-level impact than targeting HR-MSM, and the effects of targeting both groups were almost additive. PrEP efficiency was predicted to be low but improved over time, with a median of 475 and 33 years of PrEP required per LYG after 10 and 20 years, respectively, when PrEP with 60% efficacy was used by 40% of HIV negative FSW.
Conclusions: PrEP targeted to high-risk MSM or FSW in Bangalore could substantially reduce incidence amongst these groups, and have a small impact upon HIV incidence in the whole population, but may not be a very efficient use of resources over the short term.

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