Gonorrhea (GC) and Chlamydia (CT) Infection in a Large, Well-Characterized Military Cohort: Prevalence, Incidence, Site of Infection, and Patient Characteristics

Background In the US military, routine extra-genital (EG) GC/CT testing in persons living with HIV was implemented in 2012. This study examines the prevalence/incidence and risk factors associated with genital (GU) and EG GC/CT infections in the US Military HIV Natural History Study (NHS), a cohort of HIV-infected Department of Defense beneficiaries. Methods Since 2012, willing NHS subjects have undergone nucleic acid-based tests (NAAT) to identify anorectal (AR)/ pharyngeal (PH) GC/CT infections. Incident cases had a positive test following an initial negative test. Risk factors for incident GC/CT infections were assessed with a multivariate Cox proportional hazards model. Results A total of 405 GC and 457 CT infections were observed among 1998 subjects (median age 28.7 years, 94% male, 44.1% African-American [AA]); 21% of GC and 18% of CT cases were re-infections. The incidence of AR GC, PH GC, and AR CT increased over time (P = 0.02, P = 0.03 and P = 0.02, respectively). Incident GC infections were associated with younger age [HR 0.61 per 5 year increase (0.57–0.66)], AA ethnicity [HR 1.46 (1.06–2.00)], higher viral load [HR 1.63 per log increase (1.47–1.80)] and a prior history of syphilis [HR 2.20 (1.62–2.99)]. Incident CT infections were associated with younger age [HR 0.7 per 5 year increase (0.66–0.74)], male gender [HR 5.82 (1.86–18.20)], higher viral load [HR 1.61 for each log increase (1.47–1.76)], lower CD4 count [HR 0.86 per 200 cell increase (0.79–0.95)], prior GC [HR 1.55 (1.15–2.08)] and prior syphilis [HR 2.16 (1.67–2.79)]. Conclusion Incident AR GC and CT infections are increasing in the NHS and approximately 20% of infections were repeat infections. The increased incidence is attributable at-least in part to the increased uptake of EG testing. Our study highlights the importance of prevention in positive programs to reduce the risk of HIV transmission. Table. Incidence rate per 100 person-years (95% confidence interval) by site GC CT Year ARa PHa GU ARa PH GU 2012 1.3 (0.7–2.3) 1.9 (1.1–2.9) 2 (1.2–3) 2.7 (1.8–4) 1 (0.5–1.9) 4.4 (3.2–5.9) 2013 1.8 (1.1–2.6) 2 (1.3–2.8) 1 (0.6–1.7) 2.5 (1.8–3.5) 0.5 (0.2–1) 2.2 (1.5–3.1) 2014 1.2 (0.7–1.9) 1.3 (0.7–2) 1.2 (0.7–1.9) 2.4 (1.7–3.4) 0.4 (0.2–1) 1.5 (0.9–2.2) 2015 2.1 (1.4–3.1) 2.3 (1.6–3.2) 1.1 (0.6–1.8) 3.1 (2.3–4.3) 0.8 (0.4–1.5) 1.8 (1.1–2.6) 2016 2 (1.3–3) 2.4 (1.6–3.4) 1.1 (0.6–1.8) 3.8 (2.7–5) 0.8 (0.4–1.5) 1.5 (0.9–2.4) aSignificant change over time. Disclosures All authors: No reported disclosures.