Syphilis and its correlates among heterosexual males attending sexually transmitted infection clinics - observation from a multicity cohort in Jiangsu Province, China.

Objectives: To estimate the prevalence of HIV and syphilis, incidence of syphilis and to identify the correlates of syphilis infection among heterosexual male attendees of sexually transmitted infection (STI) clinics (MSC).

Methods: A cohort study of one-year duration was conducted in Yangzhou and Changzhou cities in Jiangsu province of China. The baseline survey commenced in June 2009, recruited 1225 consenting adult MSCs (609 in Yangzhou and 617 in Changzhou) through STI-clinic based convenience sampling.

Results: Baseline HIV and syphilis prevalence were 0.49% and 17.29% respectively. Syphilis incidence rate was 7.22 per 100 person-years (6.53 in Yangzhou and 7.76 in Changzhou) during the 6-month follow-up with retention fractions of 27.38% and 35.15% for Yangzhou and Changzhou respectively. Majority of the participants were middle-aged, high school educated, married, living with partners and non-migrants. Very few subjects reported recent and consistent condom-use with regular partners. Although considerable number of MSCs reported recent sexual exposure with female sex workers (FSW) and non-FSW casual partners, the proportion of reported condom use was very low during those exposures. In multivariate analyses higher age, having recent sex with FSWs and being HIV-positive were associated with higher syphilis sero-positivity while higher education was protective. In bivariate analyses, being married, divorced/widowed, official residency of the study cities and non-use of condom with regular partners predicted higher risk.

Conclusions: Considering the potential bridging role of MSCs between high and low-risk populations, effective intervention strategies among them targeting the correlates of syphilis infection are urgently called for in Jiangsu province of China.