%0 Journal Article %A S J Reynolds %A A R Risbud %A M E Shepherd %A A M Rompalo %A M V Ghate %A S V Godbole %A S N Joshi %A A D Divekar %A R R Gangakhedkar %A R C Bollinger %A S M Mehendale %T High rates of syphilis among STI patients are contributing to the spread of HIV-1 in India %D 2006 %R 10.1136/sti.2005.015040 %J Sexually Transmitted Infections %P 121-126 %V 82 %N 2 %X Background: Recent syphilis outbreaks have raised concern regarding the potential enhancement of HIV transmission. The incidence of syphilis and its association with HIV-1 infection rates among a cohort of sexually transmitted infection (STI) clinic attendees was investigated. Methods: 2732 HIV-1 seronegative patients attending three STI and one gynaecology clinic, were enrolled from 1993–2000 in an ongoing prospective cohort study of acute HIV-1 infection in Pune, India. At screening and quarterly follow up visits, participants underwent HIV-1 risk reduction counselling, risk behaviour assessment and HIV/STI screening that included testing for serological evidence of syphilis by RPR with TPHA confirmation. Patients with genital ulcers were screened with dark field microscopy. Results: Among 2324 participants who were HIV-1 and RPR seronegative at baseline, 172 participants were found to have clinical or laboratory evidence of syphilis during follow up (5.4 per 100 person years, 95% CI 4.8 to 6.5 per 100 person years). Independent predictors of syphilis acquisition based on a Cox proportional hazards model included age less than 20 years, lack of formal education, earlier calendar year of follow up, and recent HIV-1 infection. Based on a median follow up time of 11 months, the incidence of HIV-1 was 5.8 per 100 person years (95% CI 5.0 to 6.6 per 100 person years). Using a Cox proportional hazards model to adjust for known HIV risk factors, the adjusted hazard ratio of HIV-1 infection associated with incident syphilis was 4.44 (95% CI 2.96 to 6.65; p<0.001). Conclusions: A high incidence rate of syphilis was observed among STI clinic attendees. The elevated risk of HIV-1 infection that was observed among participants with incident syphilis supports the hypothesis that syphilis enhances the sexual transmission of HIV-1 and highlights the importance of early diagnosis and treatment of syphilis. %U https://sti.bmj.com/content/sextrans/82/2/121.full.pdf