High rates of subsequent asymptomatic STIs and risky sexual behavior in patients initially presenting with primary HIV-1 infection

Abstract

Introduction

Knowledge of the characteristics and risk factors of individuals with an asymptomatic sexually transmitted infection (STI) is essential for implementation of targeted STI screening strategies.

Methods

Between June 2015 and January 2017 an STI screening was offered to all participants in the Zurich Primary HIV-1 Infection Study. Patients were tested for gonorrhea, chlamydia, syphilis, and hepatitis C virus. Determinants of STI prevalence and incidence were assessed using mixed-model logistic regression and survival analysis.

Results

Out of 214 participants, 174 (81%) were screened at least once. Most patients were men-who-have-sex-with-men (MSM) (87.4%). Presenting with a primary HIV-infection was associated with higher odds for later risky sexual behavior, as compared to presenting in the chronic phase (OR 5.58 (95% C.I 3.68–8.8)). In total, 79 STIs were detected reflecting a high period prevalence of 33.3% (58/174). Sixty-six percent (52/79) were asymptomatic. Most common STIs were chlamydia (50.6%, 40/79), gonorrhea (25.3%, 20/79), syphilis (19%, 15/79), and acute hepatitis C infection (3.8%, 3/79). In a multivariable model, engaging in insertive (OR 6.48 95%C.I 1.14–36.76) or both insertive and receptive (OR 4.61 95%C.I 1.01–20.96) anal intercourse, STI symptoms (OR 3.4 95%C.I 1.68–6.89) and condomless sex (OR 2.06 95%C.I 1.14–3.74) positively correlated with a positive screen. The hazard of an incident STI increased with the presence of STI symptoms (HR 3.03 95%C.I. 1.17–7.84) and any recent drug use (HR 2.63 95%C.I. 1–6.9).

Conclusions

A trimonthly STI screening including asymptomatic individuals should be considered in this population, particularly in MSM who report sexual risk behavior.