Background: The rise in sexually transmitted infections and chemsex has led to syndemy with HIV, partly due to common routes of transmission and clustered transmissions. Despite this, barriers to STI care and PrEP still remain. We sought to determine whether MSM at low risk for HIV infection were also at low risk for other STIs.
Methods: The study group was tested for HIV, HCV, and Treponema pallidum, as well as had urethral, rectal, and oropharyngeal smears performed for Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) six months apart. The control group was tested once to define the background incidence.
Results: Treponema pallidum, CT, and NG prevalence was very high at both time points and was similar to the control group. CT was especially common in the control group (20.58%) and the study group at the rectal site at the second time point (9.37%). NG dominated the oropharyngeal site (15.87%), with urethral site sparing. NG infection was associated with an increased number of partners, not condom use (OR, 1.082 [95% CI; 1.009-1.171]). Risk behavior did not change between the time points. Treponema pallidum, CT, and NG incidence was exceptionally high (12.5/100PY, 25.39/100PY, 34.92/100PY, respectively; pooled 87.5/100PY) and was comparable to other studies of high-risk MSM.
Conclusions: Despite a lower risk for HIV acquisition, the study group was at a very high risk for other STIs, and this risk remained high throughout the study. Patients and medical professionals should be aware of syphilis, gonorrhea, and chlamydiosis transmission risks, and screening should be performed accordingly. Prophylactic programs need to be updated to specifically include lower-risk individuals.
Keywords: Chlamydia trachomatis; HIV; Neisseria gonorrhoeae; PrEP; STI; syphilis.