High Prevalence of Anal Sexually Transmitted Infections among Men Who Have Sex with Men and Transgender Women Attending a Clinic for Prevention of Anal Cancer in Salvador, Brazil

Abstract

Men who have sex with men (MSM) and transgender women (TGW) are highly vulnerable to anal sexually transmitted infections (STIs). Objectives—to evaluate the prevalence of anal STIs among MSM and TGW attending a referral clinic for anal cancer prevention. Methods—MSM and TGW attending a medical visit for high-resolution anoscopy in Salvador, Brazil, from February 2021 to June 2022 were screened for HPV, gonorrhea, and chlamydial infection by PCR of anal swab and by serum VDRL titration for syphilis screening. They also responded to a questionnaire on sociodemographic characteristics and sexual behavior. Results—we evaluated 141 participants: 117 (82.9%) MSM, 9 (6.4%) bisexual men (BSM), and 15 (10.6%) TGW. Most (111/141, 78.7%) were older than 30 years, 89 (63.1%) had over 12 years of education, and 124 (87.9%) had a family income of up to five minimum wages. At least one STI was detected in 112 (79.4%) of the participants (86.7% among TGW). HIV infection was detected in 102 (72.3%) participants; HIV frequency was higher in BSM (7/9, 88.9%) and in MSM (89/116, 76.1%) than in TGW (5/15, 33.3%). A lower income (p = 0.004) was predictive of anal STIs, while syphilis was significantly more frequent among participants with HIV (29.1% vs. 5,3%, for HIV positive and negative, respectively, p = 0.002). Presenting at least one active STI was also associated with having had group sex in the last year (p = 0.03) and with use of sexualized drugs (p = 0.02). Conclusions—MSM and TGW present a high vulnerability to anal STIs. Number of sexual partners, use of sexualized drugs, and lower income are predictive of a higher risk of acquiring an STI in such populations.