Background Rectal Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infection have been neglected and epidemiological data is not available in Japan. Thus, we evaluated prevalence and incidence of rectal CT and NG in non HIV-infected men who have sex with men (MSM) cohort, Sexual Health Clinic (SHC) established in National Center for Global Health and Medicine (NCGM), in Tokyo in January 2017.

Methods Non HIV-infected MSM with aged 16 years old and over were included in SHC. Prevalence of rectal CT/GC infection in SHC were compared with those of an existing HIV-infected MSM cohort in NCGM. The participants of SHC were examined HIV infection and rectal and pharyngeal CT/NG every 3 months. Urethral CT/NG infection were evaluated at physician’s discretion. Incidence rate of HIV, CT and NG were evaluated at the time of December 2018.

Results 502 MSM had been included into SHC by December 2018 and 13 were diagnosed with HIV infection at the enrollment and excluded. 561 HIV-infected MSM were evaluated rectal CT/NG infection cross-sectionally. Between the two cohorts, mean age was 33.6 and 46.4 years old (p<0.001). Prevalence of rectal CT or NG infection were 18.4% and 16.8% (p=0.483). Prevalence of rectal CT was 16.4% and 15.5% (p=0.707) and prevalence of NG was 4.1% and 2.3% (p=0.101). Of the 489 subjects in SHC, 326 were followed at least twice, with 291.8 person-years during the study period. The incidence of HIV, rectal CT and NG infection were 3.8, 18.8, 4.9/100 person-year. The incidence of pharyngeal CT and NG infection were 1.5 and 8.3/100 person-year. 33.8% of the incidental cases were recurrent infection. In this study, HIV seroconversion was not associated with rectal CT or NG infection at the enrollment (p=0.438).

Conclusion The prevalence and incidence of rectal CT and NG infection are high among MSM in Tokyo, which requires urgent countermeasures.

Disclosure No significant relationships.