Symptoms, Sites, and Significance of Mycoplasma Genitalium in Men Who Have Sex With Men

Tim R.H. Read; Gerald L. Murray; Jennifer A. Danielewski; Christopher K. Fairley; Michelle Doyle; Karen Worthington; Jenny Su; Elisa Mokany; L.T. Tan; David Lee; Lenka A. Vodstrcil; Eric P.F. Chow; Suzanne M. Garland; Marcus Y. Chen; Catriona S. Bradshaw


Emerging Infectious Diseases. 2019;25(4):719-727. 

In This Article

Abstract and Introduction


During 2016–2017, we tested asymptomatic men who have sex with men (MSM) in Melbourne, Australia, for Mycoplasma genitalium and macrolide resistance mutations in urine and anorectal swab specimens by using PCR. We compared M. genitalium detection rates for those asymptomatic men to those for MSM with proctitis and nongonococcal urethritis (NGU) over the same period. Of 1,001 asymptomatic MSM, 95 had M. genitalium;84.2% were macrolide resistant, and 17% were co-infected with Neisseria gonorrhoeae or Chlamydia trachomatis. Rectal positivity for M. genitaliumwas 7.0% and urine positivity was 2.7%. M. genitalium was not more commonly detected in the rectums of MSM (n = 355, 5.6%) with symptoms of proctitis over the same period but was more commonly detected in MSM (n = 1,019, 8.1%) with NGU. M. genitalium is common and predominantly macrolide-resistant in asymptomatic MSM. M. genitalium is not associated with proctitis in this population.


Mycoplasma genitalium causes nongonococcal urethritis (NGU) in men and is associated with pelvic inflammatory disease (PID), spontaneous abortion, and premature labor in women.[1,2] Most guidelines recommend azithromycin as a first-line treatment; however, macrolide resistance is widespread and increasing in many countries.[3–5] In a recent study of M. genitalium urethritis in Melbourne, Victoria, Australia, 39% of cases were in men who have sex with men (MSM); macrolide resistance was detected almost twice as often in MSM as in women or heterosexual men (76% of MSM vs. 39% for women and heterosexual men combined; p = 0.005).[6] We hypothesized that this difference may have arisen from frequent treatment of MSM for Chlamydia trachomatis and Neisseria gonorrhoeae infections, resulting in exposure of asymptomatic M. genitalium infections to azithromycin.

M. genitalium has been proposed as a cause of proctitis in MSM, but few studies have examined this association. Soni et al. found M. genitalium in 4.4% of rectal swabs from 438 MSM in England and found no association with rectal symptoms.[7] Francis et al. found M. genitalium in 5.4% of rectal swabs from 500 MSM in the United States but found only a weak association with rectal symptoms.[8] Bissessor et al. reported that bacterial load of rectal M. genitalium was higher in MSM with proctitis compared with those with asymptomatic infection, and detection was more common in HIV-positive than HIV-negative MSM (21% vs. 8%; p = 0.006).[9] A meta-analysis in 2009 of 19 mostly cross-sectional or case–control studies found an association between M. genitalium and HIV infection, particularly in studies from sub-Saharan Africa.[10] Subsequently, M. genitalium was detected twice as commonly in women who seroconverted to HIV in a prospective study in Africa,[11] but no equivalent studies in MSM are available.

We aimed to determine the proportion of asymptomatic MSM who had M. genitalium in the urethra or rectum and the prevalence of macrolide resistance and risk factors for infection. We compared these data with the proportion of tests positive for M. genitalium in MSM with symptoms of proctitis and nongonococcal urethritis to further examine the contribution of M. genitalium to these syndromes in MSM.