Potential for Asymptomatic Mycoplasma genitalium Testing

Although there is a limited understanding of Mycoplasma genitalium infection, it is associated with certain behaviors and subpopulations that could be targeted for infection control, according to a study published in Epidemiology.

Sexually transmitted infections (STIs) are a major global problem. The World Health Organization has proposed goals of reducing the incidence of certain STIs, such as Neisseria gonorrhoeae, by 90% by 2030. However, despite efforts, the number of cases of gonorrhea and chlamydia continue to rise annually, and they continue to rise especially in high-risk subpopulations, which include men who have sex with men. Traditionally, gonorrhea and chlamydia infections are managed after symptoms present, but in recent attempts to control spread of these infections, rapid testing and treatment STI services have implemented for asymptomatic patients.

However, these programs may result in selection pressure for antibiotic resistance development in M genitalium along with gonorrhea if undetected co-infections are present and azithromycin is prescribed. In men, M genitalium accounts for 15% to 20% of nongonococcal urethritis; in women, M genitalium is associated with cervicitis, pelvic inflammatory disease, preterm birth, and spontaneous abortion. Azithromycin is the first-line treatment, but widespread use for syndromic management of STIs has contributed to the emergence of macrolide-resistant M genitalium. As a result of the lack of data and medical experts wanting to avoid widespread asymptomatic screenings, asymptomatic testing is not currently recommended. Therefore, this study aimed to estimate the prevalence of M genitalium and macrolide resistance among asymptomatic people visiting a point-of-care service for rapid STI screening and identified risk factors associated with the acquisition of this infection.

In total, 890 asymptomatic participants attending an STI screening service in Barcelona, Spain, were included and were tested for M genitalium and macrolide resistance, using the molecular ResistancePlus M genitalium assay (SpeeDx, Australia). Participants who were asymptomatically infected were invited to attend the STI Unit for resistance-guided antimicrobial therapy.

Results suggested that there are insufficient data to justify M genitalium testing among asymptomatic individuals. In total, 66 (7.4%) of participants had M genitalium prevalence, which was higher among men who have sex with men when compared with heterosexual men and women (P =.012). Similarly, macrolide resistance was higher in men who have sex with men when compared with heterosexual men and women (P <.001). Co-infection with M genitalium was found in 8.5% of participants with either chlamydia or gonorrhea. Behaviors that were significantly associated with M genitalium infection included men having sex with men, receptive anal intercourse, syphilis history, HIV-positive status, and high-risk sexual activity, defined as more than 5 sexual partners in the last 3 months. This suggested that these subpopulations could be potential targets for M genitalium screening in an attempt to control infection. Further, 36 of the 66 participants that had an M genitalium prevalence underwent the resistance-guided therapy approach which demonstrated high efficacy in eradicating M genitalium infections and preventing new M genitalium macrolide-resistant cases.

Overall, the study authors concluded that, “Nevertheless, current available evidence is insufficient to justify [M genitalium] screening among any defined asymptomatic population. So, current guidelines should be followed until more empirical studies improve the understanding of [M genitalium] natural history and assess the cost and effectiveness of screening.”

Reference

Fernandez-Huerta M, Barbera MJ, Esperalba J, et al. Prevalence of Mycoplasma genitalium and macrolide resistance among asymptomatic people visiting a point of care service for rapid STI screening: a cross-sectional study [published online August 26, 2019]. Sec Transm Infect. doi:10.1136/sextrans-2019-054124