Prevalence of Mycoplasma genitalium and macrolide resistance in rectal and urine samples among men who have sex with men in Sweden

Objectives While Mycoplasma genitalium is reported as a common rectal infection among men who have sex with men (MSM), published data refer predominantly to urethral infections. Currently, most guidelines recommend M. genitalium testing from urine in men with symptomatic, non-gonococcal urethritis. Macrolide resistance-associated mutations (MRMs) among M. genitalium have increased during the last decade especially among MSM. We aim to demonstrate the prevalence and anatomical distribution of M. genitalium infection and MRM in urine and rectal specimens among MSM in Sweden. Methods In this cross-sectional study in 2019, paired urine and rectal samples from symptomatic and asymptomatic MSM attending a sexually transmitted infection clinic in the south of Sweden were screened for M. genitalium, presence of MRM, Neisseria gonorrhoeae, Chlamydia trachomatis, HIV and syphilis. Results The overall prevalence of M. genitalium was 10.5% (64 of 609), rectal samples 7.6% (46 of 609) and urine samples 3.9% (24 of 609) (p=0.007). Among M. genitalium-positive cases, single rectal and single urethral infection was detected in 62.5% (40 of 64) and 28.1% (18 of 64), respectively (p<0.0001). Infection at both sites was seen in 9.4% (6 of 64). The prevalence of MRM was 67.9% (19 of 28). M. genitalium was significantly associated with HIV (OR 2.60, 95% CI 1.14 to 5.88, p=0.02). Among the MSM, 7.4% (45 of 609) were infected with N. gonorrhoeae, 6.7% (41 of 609) with C. trachomatis, 7.1% (43 of 609) with HIV and 0.7% (4 of 609) with syphilis. Conclusions In this study, among MSM, most infections with M. genitalium were detected as rectal mono infections. The prevalence of M. genitalium among MSM was almost twofold higher in rectal samples (7.6%) compared with urine samples (3.9%). The prevalence of macrolide resistance was high with no difference between urine and rectal samples.