Risk profile of female sex workers who participate in a routine penicillinprophylaxis programme in Surabaya, Indonesia

We conducted a sexually transmitted disease (STD) prevalence survey of 1867 female sex workers in Surabaya, Indonesia, some of whom reported participa tion in a routine penicillin prophylaxis programme. In Surabaya, 34% of fem ale sex workers had received a prophylactic penicillin injection programme from the government within 28 days. Sex workers who had received routine pr ophylaxis injection were more likely to be less educated, to work in brothe l complexes, and to have more customers per week than other sex workers. Th e prevalence rates of syphilis, gonorrhoea, chlamydia, and trichomoniasis w ere higher among sex workers who received the routine penicillin treatment than among those who had not received antibiotic treatment in the last 28 d ays. However, after adjustment for age, education, fee per sex act, number of customers, and condom use in the previous 7 days, only trichomoniasis wa s still significantly different (adjusted odds ratio of 3.2). High-risk wom en were more likely to participate in the routine penicillin prophylaxis pr ogramme. The lack of a demonstrable individual-level protection from this p rophylaxis treatment programme in this cross-sectional study appears due to differential uptake of penicillin prophylaxis by women at higher presumpti ve risk for STD. Randomized clinical trials and mathematical modelling, tog ether with observational data such as presented here, all can contribute to optimal understanding of a complex intervention like mass chemoprophylaxis for STD among female sex workers.