Clinical epidemiology and management challenges of genital Mycoplasma and Ureaplasma infections: a retrospective observational study at a Japanese urban clinic

BACKGROUND: Genital Mycoplasmas and Ureaplasmas pose diagnostic and therapeutic challenges due to their varying pathogenicity and increasing antimicrobial resistance. This study aimed to characterise the positivity, clinical associations, and treatment outcomes of Mycoplasmoides genitalium, Metamycoplasma hominis, Ureaplasma urealyticum and Ureaplasma parvum in an urban clinic in Tokyo, Japan. METHODS: This retrospective study was conducted at a single clinic in Tokyo, Japan. Electronic medical records of patients who underwent polymerase chain reaction testing for the four target pathogens between January 2023 and April 2024 were included in the study. To minimise confounding, a sub-analysis was performed on a chlamydia/gonorrhoea-negative subset. The statistical association between specific organisms and symptoms was assessed, and the treatment success rate (negative test-of-cure after ≥3 weeks) was evaluated. RESULTS: Of 524 patients tested, 213 (40.7%) tested positive for at least one pathogen. M. genitalium was the most prevalent (81/213, 38.0%), and showed a robust association with dysuria (P < 0.01) and purulent genital discharge (P = 0.03) in the chlamydia/gonorrhoea-negative subset. In contrast, M. hominis and Ureaplasma spp. were predominantly associated with colonisation or non-specific symptoms. The clinical success rate for M. genitalium (minocycline followed by sitafloxacin) was suboptimal at 68.8%. Notably, U. parvum showed an alarmingly low success rate against moxifloxacin (28.6% in the subset). The overall test-of-cure completion rate was low (60.1%). CONCLUSIONS: In a Tokyo clinical setting, M. genitalium was the most prevalent species and the primary driver of symptoms, whereas M. hominis and Ureaplasma spp. frequently suggest colonisation. Management remains challenging due to suboptimal cure rates and poor follow-up adherence. These findings support a tiered diagnostic strategy that prioritises exclusion of major sexually transmitted infections and emphasises species-specific management.