[Early diagnosis and correlations of sexually transmitted infections among women in primary care health services].

Introduction: Sexually Transmitted Infections (STIs) in women remain a public health challenge due to high prevalence, difficulties to implement early diagnosis strategies and high rates of complications.
Objective: Identify the prevalence of STIs among users of a primary health care clinic in São Paulo.
Methods: Women, 18 to 40 years of age, were invited to self-collect vaginal specimens to be tested for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis by Polymerase Chain Reaction (PCR). Women were also invited to answer a demographic and sexual history questionnaire, either on the computer or face-to-face.
Results: The prevalence of STIs obtained from the 781 women included in the study was: Chlamydia trachomatis: 8.4%, Neisseria gonorrhoeae: 1.9%, and Trichomonas vaginalis: 3.2%. Thirteen percent tested positive for at least one out of the three STIs. The variables associated independently with a higher risk of STIs were: age under 20-years-old, more than two lifetime sexual partners, and self-perception of STI risk. The use of condoms as a contraceptive method proved to be a protective factor.
Conclusion: The high prevalence found among these women indicates the need for the implementation of STI screening strategies in primary care settings in Brazil.