Background: The global epidemic of Mycoplasma genitalium (MG) is marked by its widespread prevalence, varied resistance patterns, and significant impact on sexual health. This study aimed to understand the prevalence and interaction of MG infections with other sexually transmitted infections (STIs) in a low-resource setting, as well as the implications for routine STIs care.

Methods: This nested cross-sectional study was conducted from July 2022 to April 2023 across six outpatient care sites in Shiselweni, Eswatini. Participants completed a self-questionnaire, underwent syndromic case management, and provided urine samples for parallel molecular-based testing using the Cepheid GeneXpert® platform for MG, Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Trichomonas vaginalis (TV). The proportion of MG mono-infection and coinfections were calculated. Multivariable logistic regression models identified predictors of symptomatic MG mono-infections, which could be used to streamline at-risk patients for MG testing.

Results: Among 735 participants, the median age was 27 (interquartile range 23-34) years, 65.9% were women, and 9.5% were HIV-positive. MG infection was detected in 10.5% (n = 77) of clients, with 45.5% (n = 35) coinfected with any of CT/NG/TV, and one case (0.1%) showing macrolide resistance. Among women with vaginal discharge syndrome (28.1%, n = 136), 0.7% (n = 1) had MG mono-infection, and 10.3% (n = 14) had MG and CT/NG/TV coinfections. Among men with male urethral syndrome (31.9%, n = 80), 3.8% (n = 3) had MG mono-infection, and 2.5% (n = 2) had MG and CT/NG/TV coinfections. Most MG-positive cases (66.2%, n = 51) did not receive antibiotic therapy, despite 68.6% (n = 35) reporting symptoms of STIs. Of treated cases, 26.0% (n = 20) received azithromycin monotherapy, 6.5% (n = 5) doxycycline monotherapy, and 1.3% (n = 1) both drugs. Of 305 individuals reporting STIs symptoms but tested negative for CT/NG/TV, 23 (7.5%) had symptomatic MG mono-infections. Unemployment and never having been tested for HIV were identified as risk factors. Streamlining 108/305 (35.4%) at-risk individuals for molecular-based MG testing would identify 14.8% (16/108) as positive, capturing 69.6% (16/23) of all symptomatic MG mono-infections.

Conclusions: MG was common among outpatients and frequently co-occurred with CT, NG, and TV infections. Syndromic case management often misclassified MG infections, leading to ineffective treatment. Expanding molecular-based MG testing could enhance antibiotic stewardship, crucial for preventing the spread of drug-resistant strains.