Socio-demographic and behavioural factors associated with high incidence of sexually transmitted infections in female sex workers in Madagascar following presumptive therapy

Background: Too little is known about the many women who generate income in Madagascar by trading sex. Methods: Clinical and laboratory exams were offered to 493 non-care seeking female sex workers (SWs) in Antananarivo and 493 in Tamatave. SWs were recruited by peers in their community; they were interviewed, counselled and treated for sexually transmitted infections (STIs) at recruitment and re-evaluated 2 months later. Results: One hundred and eighty six (38%) of the SWs in Antananarivo and 113 (23%) in Tamatave did not complete primary school (P < 0.0001). The incidence rates per person per month in Antananarivo and Tamatave, respectively, were 0.09 and 0.08 for gonorrhoea; 0.05 and 0.03 for chlamydia; 0.24 and 0.15 for trichomoniasis; 0.07 and 0.05 for syphilis. At follow-up, consistent condom use with clients was reported by 56 (12%) SWs in Antananarivo and 137 (29%) in Tamatave (P < 0.0001); 320 (70%) SWs in Antananarivo and 11 (2%) in Tamatave reported sex with a non-paying partner in the past month (P < 0.0001). In Antananarivo, 422 (92%) of the SWs thought they were at no or low risk of having an STI compared to 100 (21%) in Tamatave (P = 0.02). At follow-up, 277 (61%) SWs reported no birth control for their last sex act in Antananarivo, compared to 26 (5%) in Tamatave (P < 0.0001). Socio-demographic and behavioural risk factors for incident gonorrhoea, chlamydia and trichomoniasis varied by city. Conclusions: Strategies to address the needs of women who trade sex should include educational and economic opportunities; should tackle male partners of SWs; promote dual protection against unintended pregnancy and STIs, while taking into account local socio-demographic and behavioural characteristics.