Mycoplasma genitalium was previously less common among men who have sex with men (MSM) compared with men with only female partners (MSW) in men with nongonococcal urethritis (NGU) in Sydney, Australia. We aimed to determine the prevalence of M. genitalium and of macrolide-resistant M. genitalium in men with NGU and to compare differences between prevalence and resistance rates between MSM and MSW.
We enrolled 588 men with NGU in a prospective study at two urban sexual health services. The ResistancePlus MG assay (SpeeDx, Australia) was used to detect both M. genitalium, and macrolide resistance-associated mutations in first-void urine samples. Demographic, behavioral and clinical data were analyzed to investigate associations with M. genitalium infection or the presence of macrolide resistance.
Mycoplasma genitalium prevalence was 12.8% (75 of 588) overall and among MSM (12.8% [39 of 306]) and MSW (12.8% [36 of 282]; risk ratio [RR], 1.00; 95% confidence interval [CI], 0.65–1.52). Overall, 70.7% (53 of 75) of M. genitalium strains were macrolide-resistant, with significantly more resistance among MSM (89.7%, 35 of 39) than MSW (50%, 18 of 36) (RR, 1.80; 95% CI, 1.27–2.54; P = 0.001). On multivariate analysis, the presence of M. genitalium macrolide resistance mutations was independently associated with having male sexual partners compared with having only female partners (RR, 1.55; 95% CI, 1.02–2.38; P = 0.042).
Prevalence of M. genitalium among men with NGU is now similar for MSW and MSM and has increased locally from 5.2% to 12.8% within the last 10 years. Men who have sex with men are significantly more likely than MSW to harbor macrolide-resistant M. genitalium infections. This has treatment implications.
In a prospective study of men with nongonococcal urethritis in Sydney, among men with Mycoplasma genitalium infection, men with male sexual partners were significantly more likely than men with female partners to harbor macrolide-resistant infections.
From the *Sydney Sexual Health Centre, Sydney, New South Wales;
†Centre for Infectious Diseases and Microbiology Laboratory Services, ICPMR-NSW Health Pathology, Westmead;
‡School of Public Health and Community Medicine, University of New South Wales, Sydney;
§Western Sydney Sexual Health Centre, Parramatta, New South Wales;
¶Marie Bashir Institute for Infectious Diseases and Biosecurity, University of Sydney, Sydney, Australia
The authors thank Associate Professor Iryna Zablotska for advice on the statistical analysis.
Conflict of Interest and Sources of Funding: SpeeDx (Sydney, New South Wales, Australia) is the manufacturer of the ResistancePlus MG assay and supplied the kits used in this study free-of-charge. All other authors declare no conflict of interests.
All authors contributed to the study design and reviewed and contributed to the article. R.M., A.M., D.L.C., and M.P. planned and conducted clinical procedures and collected clinical data. D.J., N.J., and S.C. planned and conducted laboratory procedures. D.L.C. performed statistical analysis and R.M. wrote the initial draft with the exception of the laboratory methods which were written by D.J. All the authors contributed to the final article.
The study was reviewed and approved by the South Eastern Sydney Human Research Ethics Committee for Sydney Sexual Health Centre and the Western Sydney Human Research Ethics Committee for Western Sydney Sexual Health Centre.
Correspondence: Ruthy McIver, Sydney Sexual Health Centre Level 3, Nightingale Wing Sydney/Sydney Eye Hospital, Sydney, NSW, Australia, 2000. E-mail: email@example.com.
Received for publication January 24, 2019, and accepted April 11, 2019.
Online date: April 18, 2019