163. High Prevalence of Urogenital and Rectal Mycoplasma genitalium in U.S. MSM with a History of STIs in the Last Year
Authors: Bainbridge Emma D , Soge Olusegun O , Grabow Cole , Cohen Stephanie , Dombrowski Julia C , Fairbanks Jade , Celum Connie , Luetkemeyer Annie 
Published: December 2021

Abstract

Background
M. genitalium (M. gen) is an under-recognized sexually transmitted bacterial pathogen that causes 15-25% of nongonococcal urethritis (NGU) in men. Asymptomatic M. gen may serve as a reservoir, lead to transmission to sexual contacts, and drive the development of drug resistance. M. gen may be associated with an increased risk of HIV acquisition, as seen in some studies. Data are limited on M. gen prevalence among U.S. men who have sex with men (MSM) living with HIV or HIV-uninfected and on pre-exposure prophylaxis (PrEP).

Methods
We analyzed baseline prevalence of urogenital and rectal M. gen using the Aptima Mycoplasma genitalium nucleic acid amplification test in participants enrolled in DoxyPEP, an ongoing randomized, open label trial of the effectiveness of doxycycline post-exposure prophylaxis (PEP) on incidence of gonorrhea, chlamydia, and early syphilis among MSM and transgender women living with HIV or on PrEP in San Francisco and Seattle (NCT03980223). Participants completing at least one follow up visit were also assessed for M. gen persistence, clearance, and incidence. Testing was at regular intervals and not symptom driven.

Results
This analysis included 122 men; 34% with HIV and 66% on PrEP. In the prior 12 months, 18.9% had a diagnosis of syphilis, 58.2% chlamydia, and 63.9% gonorrhea. At baseline, M. gen was present in at least one site in 24%; 9% in the urine and 16% in the rectum, with 1 testing positive at both sites. M. gen presence was not associated with age, ethnicity, race, HIV status, number of partners in the past 3 months, or bacterial STI in the past 3 months. 65 participants had follow up tests a median of 9.1 months after baseline (IQR 7.8-9.8); among 7 participants with urogenital M. gen at baseline, M. gen cleared in 6 and persisted in 1. Among 11 participants with rectal M. gen at baseline, M. gen cleared in 4 cleared and persisted in 7. At follow up, M. gen was detected in 2 urine and 9 rectal specimens in those previously negative at these sites.

Figure 1. Baseline prevalence of urogenital and rectal M. genitalium in MSM at high risk for STIs enrolled in DoxyPEP

Figure 2. Detection of urogenital and rectal M. genitalium among participants with baseline and follow up testing

Conclusion
In this cohort of MSM with a recent diagnosis of a bacterial STI, routine testing identified urogenital or rectal M. gen in 24% of participants at baseline and 31% at either baseline or follow-up. The association of persistent M. gen with the risk for subsequent symptomatic infection and drug resistance merits further investigation.

Disclosures
Emma D. Bainbridge, MD, MPH, Hologic (Grant/Research Support) Olusegun O. Soge, PhD, Hologic Inc. (Grant/Research Support)SpeeDx Inc. (Grant/Research Support) Annie Luetkemeyer, MD, Cepheid (Grant/Research Support)Hologic (Grant/Research Support)Mayne Pharma (Grant/Research Support)