The high risk of an HIV diagnosis following a diagnosis of syphilis: a population-level analysis of New York City men

Clin Infect Dis. 2015 Jul 15;61(2):281-7. doi: 10.1093/cid/civ289. Epub 2015 Apr 13.


Background: Epidemiologic studies have shown that syphilis is associated with risk for human immunodeficiency virus (HIV) infection. We used population-level syphilis and HIV data to quantify HIV incidence among men following primary or secondary (P&S) syphilis diagnoses and identify the highest-risk subgroups for intensified prevention, such as pre-exposure prophylaxis with antiretroviral medications.

Methods: Male cases reported to the New York City HIV/AIDS and Sexually Transmitted Disease (STD) surveillance registries were matched using a deterministic algorithm. We measured HIV incidence following P&S syphilis diagnosed between 2000 and June 2010 and identified risk factors for HIV infection using Cox proportional hazards models.

Results: Of 2805 men with syphilis contributing 11 714 person-years of follow-up, 423 (15.1%) acquired HIV; annual incidence was 3.61% (95% confidence interval [CI], 3.27%, 3.97%). HIV incidence was high among: men who have sex with men (MSM) (5.56%, 95% CI, 5.02%-6.13%); males with secondary compared with primary syphilis (4.10% vs 2.64%, P < .0001); and males diagnosed with another bacterial STD after syphilis (7.89%, 95% CI, 6.62%-9.24%).

Conclusions: HIV incidence among men diagnosed with syphilis is high; one in 20 MSM were diagnosed with HIV within a year. Our data have implications for syphilis and HIV screening and may be useful for further targeting HIV-negative populations for pre-exposure prophylaxis.

Keywords: HIV incidence; syphilis.

MeSH terms

  • Adolescent
  • Adult
  • Follow-Up Studies
  • HIV Infections / complications*
  • HIV Infections / diagnosis
  • HIV Infections / epidemiology*
  • HIV Infections / prevention & control
  • Homosexuality, Male
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • New York City / epidemiology
  • Population Surveillance
  • Risk Factors
  • Syphilis / complications*
  • Syphilis / diagnosis
  • Syphilis / epidemiology
  • Syphilis / microbiology
  • Young Adult

Supplementary concepts

  • Syphilis, primary
  • Syphilis, secondary