High Prevalence of Rectal Chlamydia and Gonorrhea Among Men Who Have Sex With Men Who Do Not Engage in Receptive Anal Sex

BACKGROUND

In the United States, annual screening for rectal gonorrhea and chlamydia is only recommended for men who report receptive anal sex (RAS), but other behaviors (e.g., rimming) may lead to rectal Chlamydia trachomatis and Neisseria gonorrhoeae acquisition.

METHODS

We enrolled individuals assigned male sex at birth who reported sex with men and denied RAS in the past 2 years or reported RAS 1 to 2 years ago but were tested and treated since last RAS. Participants enrolled in-person at the Sexual Health Clinic in Seattle, Washington (December 2019-July 2022), or online (July 2021-March 2022). Participants completed a survey that asked about 13 non-RAS behaviors and self-collected a rectal swab for gonorrhea/chlamydia nucleic acid amplification testing. We used log binomial regression to estimate the prevalence of rectal gonorrhea/chlamydia (adjusted prevalence ratio [aPR]) by behavior, adjusting for all other behaviors.

RESULTS

We enrolled 292 participants (247 in-person and 45 online); 277 (95%) had nucleic acid amplification testing results. Rectal gonorrhea/chlamydia test positivity was 14.1% overall: 10.5% for rectal chlamydia and 4.3% for rectal gonorrhea. Most participants (70%) reported ≥1 behavior that involved direct contact with their anus. We observed a higher risk of rectal chlamydia for those who did versus did not report perianal play at 12 months (aPR, 2.39; 95% confidence interval, 1.10-5.22) and 2 months (aPR, 2.21; 95% confidence interval, 1.02-4.79). This was the only behavior significantly associated with testing positive.

CONCLUSIONS

Rectal C. trachomatis and N. gonorrhoeae prevalence was high among men who deny RAS, suggesting other possible routes of acquisition. Rectal screening for those who deny RAS should be made with careful consideration of individual- and population-level effects.

Frequency and Combination of Sequential Sexual Acts That May Lead to Sexually Transmitted Infections at Different Anatomic Sites Within the Same Person

Modeling studies suggest that transmission of gonorrhea and chlamydia to multiple anatomic sites within the same person is necessary to reproduce observed high rates of extragenital gonorrhea/chlamydia. Limited empiric behavioral data support this idea. In this cross-sectional study, we enrolled individuals assigned male at birth who reported sex with men (MSM) and denied receptive anal sex (RAS) in the past 2 years. Participants enrolled in-person at the Sexual Health Clinic in Seattle, Washington (December 2019-September 2021) or online (July 2021-September 2021), and completed a sexual history questionnaire that asked about specific sexual acts and sequence of those acts during their last sexual encounter. We enrolled 210 MSM during the 16-month recruiting period. The median number of sex acts reported at last sexual encounter was 4 (interquartile range 3-5). The most commonly reported acts at last sex were: kissing (83%), receiving oral sex (82%), and insertive anal sex (65%). There was substantial variability in the sequence of acts reported; no unique sequence of sex acts was reported by more than 12% of the population. Ninety percent of participants reported sequences of behaviors that could lead to gonorrhea or chlamydia transmission within the same person (respondent or partner); the most common of these combinations was kissing followed by receiving oral sex (64% reporting). Engaging in multiple sex acts within a single sexual encounter is common and may lead to gonorrhea/chlamydia transmission within the same person. This complicates empiric measurements of transmission probabilities needed to estimate population-level transmission.