Sexually transmitted infections among female sex workers in Kupang, Indonesia: searching for a screening algorithm to detect cervical gonococcal and chlamydial infections

Abstract

Background and goal: Notifications of HIV infection in Indonesia are increasing, but there are few data on other sexually transmitted infections (STIs), especially in the eastern islands of Indonesia. We aimed to measure the prevalence of STIs among female sex workers (FSWs) in Kupang, West Timor, and to develop screening algorithms to detect cervical infections with Neisseria gonorrhoeae and/or Chlamydia trachomatis (NG/CT).

Study design: During 6 months in 1999, we recruited all the FSWs at Kupang's only brothel complex and a smaller number of independent FSWs. The women were examined at dedicated clinics and most laboratory tests were performed at provincial laboratories. Algorithms based on the strongest associations of variables with NG/CT were compared with the laboratory diagnoses.

Results: We recruited 288 women. The prevalence of N gonorrhoeae infection was 31%, that of C trachomatis infection was 24%, that of Trichomonas vaginalis infection was 5%, and that of syphilis was 13%. No case of HIV infection was detected. Few women had symptoms of STI. The only variables significantly associated with NG/CT after logistic regression analysis were the presence of cervical discharge (either yellow or clear) and a high count of polymorphonuclear leukocytes on gram-stained endocervical smear. Several algorithms to screen for NG/CT achieved high (>80%) sensitivity, but the highest specificity among these was only 50%.

Conclusions: Although several of the generated algorithms may be useful in the absence of simple, accurate, affordable diagnostic tests, the high rates of STIs in this population could justify a more aggressive strategy incorporating periodic presumptive treatment to rapidly reduce prevalence.