O4.1 - Exploring current etiologies of urethritis: associations of urethral microorganisms and urethritis among men attending 6 STD clinics in the US, 2017-2018

Introduction: Urethritis among men is known to be caused by Neisseria gonorrhoeae (NG), Chlamydia trachomatis (CT), and Mycoplasma genitalium (MG), but data supporting associations between urethritis and other microorganisms are limited. We compared the prevalence of 10 microorganisms among men with and without urethritis to examine their potential contribution to urethritis, and examined prevalence by sex/gender of sex partners.

Methods: We examined data from men who presented to one of six STD clinics in the United States with urethritis symptoms during June 2017–July 2018. We assessed urethral specimens by Gram or methylene blue/gentian violet (MB/GV) stain to diagnose urethritis (defined as ≥2 WBC per oil field immersion on ≥3 fields), and urine specimens by nucleic acid amplification test to detect NG, CT, MG, Trichomonas vaginalis, HSV-1 and -2, Neisseria meningitidis, Ureaplasma urealyticum, Ureaplasma parvum, or Mycoplasma hominis. We calculated the prevalence and 95% confidence intervals of each microorganism among men with and without urethritis by Gram or MB/GV stain.

Results: Microorganisms were detected in 83% of 918 men with urethritis and 58% of 178 men without urethritis. Microorganisms that were more prevalent among men with urethritis than men without were NG (35% vs. 0%), MG (29% vs. 11%), CT (25% vs. 10%), and T. vaginalis (7% vs. 3%) (Figure 1). Microorganisms that were more prevalent among men without urethritis than men with urethritis were N. meningitidis (7% vs. 2%), U. urealyticum (23% vs. 19%), U. parvum (19% vs. 13%), and M. hominis (11% vs. 9%), though not all differences were statistically significant. The prevalence of HSV-1 and -2 was low (< 3%) in both groups. Similar patterns were observed when stratified by sex of sex partners; T. vaginalis was only observed among men who have sex with women.

Conclusions: Consistent with other studies, NG, CT, MG, and T. vaginalis were associated with urethritis among men presenting to STD clinics. N. meningiditis, U. urealyticum, U. parvum and M. hominis were more prevalent among men without urethritis and detection of these microorganisms may represent colonization rather than infection. Investigation into the presence and effect of co-infections and larger sample sizes are needed.