No effect of test and treat on sexual behaviours at population level in rural South Africa Rolland, M. McGrath, N. Tiendrebeogo, T. /Larmarange, Joseph Pillay, D. Dabis, F. Orne-Gliemann, J. ANRS TasP Study Group Africa antiretroviral therapy HIV prevention sexual behaviour Context: Within the community-randomized ANRS 12249 Treatment-as-Prevention trial conducted in rural South Africa, we analysed sexual behaviours stratified by sex over time, comparing immediate antiretroviral therapy irrespective of CD4(+) cell count vs. CD4(+)-guided antiretroviral therapy (start at CD4(+) cell count >350 cells/mu l then >500 cells/mu l) arms. Methods: As part of the 6-monthly home-based trial rounds, a sexual behaviour individual questionnaire was administered to all residents at least 16 years. We considered seven indicators: sexual intercourse in the past month; at least one regular sexual partner in the past 6 months; at least one casual sexual partner in the past 6 months and more than one sexual partner in the past 6 months; condom use at last sex (CLS) with regular partner, CLS with casual partner, and point prevalence estimate of concurrency. We conducted repeated cross-sectional analyses, stratified by sex. Generalized Estimating Equations models were used, including trial arm, trial time, calendar time and interaction between trial arm and trial time. Results: CLS with regular partner varied between 29-51% and 23-46% for men and women, respectively, with significantly lower odds among women in the control vs. intervention arm by trial end (P<0.001). CLS with casual partner among men showed a significant interaction between arm and trial round, with no consistent pattern. Women declared more than one partner in the past 6 months in less than 1% of individual questionnaires; among men, rates varied between 5-12%, and odds significantly and continuously declined between calendar rounds 1 and 7 [odds ratio = 4.2 (3.24-5.45)]. Conclusion: Universal Test and Treat was not associated with increased sexual risk behaviours. 2019 text https://www.documentation.ird.fr/hor/fdi:010087821 fdi:010087821 Rolland M., McGrath N., Tiendrebeogo T., Larmarange Joseph, Pillay D., Dabis F., Orne-Gliemann J., ANRS TasP Study Group. No effect of test and treat on sexual behaviours at population level in rural South Africa. 2019, 33 (4), 709-722 EN AFRIQUE DU SUD