Prevalence of syphilis among antenatal clinic attendees in Karachi: imperative to begin universal screening in Pakistan.

Objectives: To assess the prevalence and associated risk factors of syphilis among antenatal clinic attendees by a multi-center cross-sectional study in Karachi, Pakistan.

Methods: We administered a structured questionnaire and obtained a blood sample for syphilis serology (rapid plasma reagin test with Treponema pallidum hemagglutination assay confirmation) from all women giving informed consent over six weeks in 2007. Prevalence was calculated at 95% confidence intervals.