WP 96 High Risk of Syphilis Infection, Reinfection and Treatment Failure Among HIV-Infected Patients in Care in North Carolina

Wednesday, September 21, 2016
Galleria Exhibit Hall
James Lewis, MD, Infectious Disease/Preventive Medicine, UNC Infectious Disease/UNC Preventive Medicine, Chapel Hill, NC, Arlene C. Sena, MD, MPH, Institute for Global Health and Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, NC, Thibaut Davy, BA, UNC Chapel Hill School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC and Sonia Napravnik, BA, BS, MPH, PhD, Infectious Disease, UNC Chapel Hill, School of Medicine, Chapel Hill, NC

Background:  A high prevalence of syphilis infection has been observed among HIV-infected populations, especially men who have sex with men (MSM). We assessed the incidence of syphilis infections, reinfections and treatment failures among HIV-infected patients seen at an infectious disease clinic in North Carolina. 

Methods:  We conducted a retrospective chart review of HIV-infected subjects enrolled in an HIV clinical cohort study between January 1996 and December 2012. Syphilis infections were identified from diagnosis codes and adjudicated by a physician in concordance with published criteria. We calculated incidence rates of syphilis infection. Subjects contributed time from their entry to care until loss to follow-up, death, or December 2015, and were followed for three years after the first syphilis diagnosis. Multivariable regression models were conducted to estimate relative risks (RR) of reinfection or treatment failure.

Results: Overall, 4,048 subjects contributed 38,352 person-years. The incidence rate of syphilis was 17 infections per 1,000 person-years; 522 (12%) patients had at least one syphilis diagnosis during the study period. After exclusion of 150 patients who were lost to follow-up or died before three years, 372 remained in the analysis including 69% MSM, 13% women and 67% Black. The stage of syphilis diagnosis was 4% primary, 16% secondary, 11% latent, 6% neurosyphilis, and 63% of unknown stage; 58 patients (16% [95% CI: 12%-20%]) met criteria for syphilis reinfection or treatment failure. In multivariable analyses, subjects with a history of ≥ 6 sexually transmitted infections had a RR of 2.85 (95% CI: 1.73, 4.69), while those with a history of hepatitis C had a RR of 0.26 (95% CI: 0.10, 0.70) for reinfection or treatment failure. 

Conclusions:  HIV infected patients are at high risk of syphilis infection, reinfection and treatment failure, reinforcing the importance of frequent testing and follow-up of sexually transmitted infections among patients in HIV clinical care.