Among men who have sex with men (MSM) using pre-exposure prophylaxis (PrEP), the prevalence of Mycoplasma genitalium (MG) infections was high and the incidence was not decreased by doxycycline postexposure prophylaxis (PEP), according to a substudy of men in the Agency for Research on AIDS and Viral Hepatitis Ipergay (ANRS Ipergay) trial. The results were published in Clinical Infectious Diseases.

Men in the ANRS Ipergay trial receive on-demand PrEP for HIV with combined tablets containing tenofovir disoproxil fumarate and emtricitabine. A total of 210 men were enrolled in this prospective study and were randomly assigned 1:1 to take 200 mg of doxycycline within 24 hours after each instance of sexual intercourse, up to a limit of 600 mg per week, or no prophylactic drug treatment.

The men were tested at baseline and at 6 months for MG in urine or with oropharyngeal or anal swabs. Resistance to azithromycin (AZM), fluoroquinolones (FQ), or doxycycline was also investigated.

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Of the 32 men who tested positive for MG, 22 were positive at baseline and 19 were positive at 6 months. The overall prevalence for all sites combined at baseline was 10.5% (95% CI, 6.7%-15.4%) and prevalence was highest in urine at 6.3%, then anal samples at 4.3%, and throat samples at 0.5%.

At 6 months, overall prevalence was 9.9% (95% CI, 6.1% to 15.0%). Of the 19 participants who were positive, 10 were in the postexposure prophylaxis (PEP) group. Prevalence in the PEP group was 10.2%, vs 9.6% in the group without PEP (P =.89).

During the 6 months of the study, the median use of doxycycline was 670 mg per month, and only 11 participants acquired a new MG infection in this time period: 7 in the PEP group and 4 in the non-PEP group. All participants were asymptomatic.

Of participants, 69.6% (16/23; 95% CI, 47%-87%) and 11.1% (3/27; 95% CI, 2%-29%) had AZM or FQ resistance mutations, respectively. At baseline, 60% of samples had AZM resistance-associated mutations, and 5.6% had FQ resistance-associated mutations. By 6 months, these rates increased to 73.3% and 13.3%, respectively.

The investigators concluded that the prevalence of MG in this cohort was high, and there was no evidence of change in prevalence among those using doxycycline PEP. Furthermore, they reported a high rate of AZM and FQ resistance along with potential tetracycline resistance mutations.

These results highlight the need for routine testing of any MG isolates obtained, in particular from MSM, before treatment and support the current recommendations to avoid testing or treatment of asymptomatic MG infection, according to the investigators.

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.


Berçot B, Charreau I, Clotilde R, et al; on the behalf of the ANRS Ipergay Study Group. High prevalence and high rate of antibiotic resistance of Mycoplasma genitalium infections in men who have sex with men. A sub-study of the ANRS Ipergay PrEP Trial. Clin Infect Dis. Published online December 11, 2020. doi:10.1093/cid/ciaa1832

This article originally appeared on Infectious Disease Advisor