1. HIV infection among young people in northwest Tanzania: the role of biological, behavioural and socio-demographic risk factors 1998-2008: randomised controlled trial of MEMA kwa Vijana adolescent sexual & reproductive health intervention – SRH education, youth friendly clinic services etc. 20 rural communities randomised to intervention (10) and control (10) arms Long-term evaluation survey conducted in 2007-8 among young people (15-30y) to assess impact of intervention on biological & behavioural outcomes. HIV and HSV-2 prevalence 1.8% and 25.8% in males 4.1% and 41.4% in females No impact of intervention on primary outcomes: HIV & HSV2 prevalence. Risk factors for HIV determined using a proximate-determinants conceptual framework & logistic regression conditional on community Francesca Lemme 1,2, Aoife Doyle 1,2, John Changalucha 3, Helen Weiss 1, Kathy Baisley 1, Kaballa Maganja 2, Deborah Watson-Jones 1,2, Saidi Kapiga 1,2, Richard Hayes 1, David Ross 1 1 London School of Hygiene & Tropical Medicine, London, UK 2 Mwanza Intervention Trials Unit, Mwanza, Tanzania 3 National Institute for Medical Research, Mwanza, Tanzania

2. Main Findings: OR of HIV infection for selected socio-demographic, behavioural and biological factors in 6476 female & 7259 male participants

3. Important implications HIV prevalence was higher in young women than young men; HSV-2 prevalence was high in both sexes HIV prevalence was associated with biological (HSV2, GUD), behavioural (number of sexual partners) and socio- demographic (age, marital status, travel from home) factors Control of GUD, HSV2 and other STIs and effective behavioural interventions are urgently needed to reduce further spread of HIV in this population A special focus on mobile young people, and those who are separated, widowed or divorced may be warranted.