A Case–Control Study of Syphilis Among Men Who Have Sex With Men in New York City

Abstract

Objective: The objective of this study was to determine factors associated with syphilis among men who report sex with other men in New York City. Design, Setting and Study Subjects: We conducted a case–control study among 88 men who reported sex with men in the previous year, 18 to 55 years old and diagnosed with primary or secondary syphilis during 2001; and 176 control subjects frequently matched by age and type of health provider. Results: HIV prevalence among syphilis cases was 48% compared with 15% among control subjects (P $30,000 per year (OR, 2.7; CI, 1.4–5.2), and barebacking (OR, 2.6; CI, 1.4–4.8). The median time since HIV diagnosis for HIV-positive was 6 years for cases and 7 years for control subjects (P = 0.70). Among HIV-infected participants, syphilis cases were more likely than control subjects to report being on antiretroviral therapy (69% vs. 44%, P = 0.05) and to report having undetectable viral load (58% vs. 24%, P = 0.02). Conclusion: HIV infection was strongly associated with syphilis in this study. High-risk behavior reported by both cases and control subjects indicates the potential for increased HIV transmission.