Mycoplasma genitalium: a common cause of persistent urethritis among men treated with doxycycline

BACKGROUND/OBJECTIVE: Persistent or recurrent non-gonococcal urethritis (NGU) is commonly observed in men attending sexually transmitted diseases clinics. The aim of this study was to determine the importance of Mycoplasma genitalium in this condition and to monitor the effect of treatment with macrolides. METHODS: 78 male patients with persistent or recurrent symptomatic non-chlamydial NGU after treatment with doxycycline 200 mg day 1 and 100 mg for the following 8 days were enrolled. The patients had a first void urine specimen examined for the presence of M genitalium DNA by an inhibitor controlled PCR. Treatment with azithromycin and/or erythromycin and/or repeat doxycycline was prescribed at the doctor's discretion to the M genitalium positive men. Microbiological cure rate was determined at a 3 week follow up visit. RESULTS: M genitalium was detected in 32 (41%) men and those infected had more often a high grade urethritis (>10 PMNLs/hpf) than those negative for M genitalium (p = 0.01). 22 men had been treated with azithromycin, 19 of whom received 1.5 g over 5 days and three received 1 g as a single dose. All 20 who came back after treatment were M genitalium negative. Only two of five erythromycin treated controlled cases were M genitalium negative after treatment compared to all six given azithromycin at inclusion (p = 0.12). Six of nine female partners were M genitalium positive; they were treated with 1.5 g azithromycin given over 5 days, and the four tested were M genitalium negative after treatment. CONCLUSIONS: M genitalium is a common cause of persistent or recurrent urethritis among men treated with doxycycline and erythromycin appears to be less efficient than azithromycin in eradicating the infection.