Prevalence, Anatomic Distribution, and Correlates of Chlamydia trachomatis and Neisseria gonorrhoeae Infections Among a Cohort of Men Who Have Sex With Men in Hanoi, Vietnam.

Background: Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) disproportionately affect men who have sex with men (MSM). Data on the prevalence, anatomical distribution, and correlates of NG and CT infections among MSM in Vietnam are limited.

Methods: Between July 2017 and April 2019, MSM 16 years or older without HIV were enrolled into an observational cohort study. Baseline data, including sociodemographics, sexual behavior, and HIV status, were collected. Testing for NG and CT were performed on urine, rectal, and pharyngeal specimens. Multivariate logistic regression models identified factors associated with NG and CT infections at baseline.

Results: In total, 1489 participants underwent NG/CT testing. The median age was 22 years (interquartile range, 20-26 years). There were 424 (28.5%) NG or CT infections: 322 (21.6%) with CT and 173 (11.6%) with NG. Rectal infections were most common for CT (73.9%), whereas pharyngeal infections were most common for NG (70.5%). Independent risk factors for CT or NG infection included ≥2 sex partners in the prior month (adjusted odds ratio [aOR], 2.04; 95% confidence interval [CI], 1.44-2.91), condomless anal sex (aOR, 1.44; 95% CI, 1.12-1.86), and meeting sex partners online (aOR, 1.35; 95% CI, 1.03-1.76). Recent genitourinary or rectal symptoms were not associated with infections.

Conclusions: The overall and extragenital prevalences of NG and CT infections were high within this sample of young MSM without HIV in Hanoi. Testing limited to urethral specimens would have missed nearly three-quarters of CT and NG infections, supporting the need for routine testing at multiple anatomic sites.