Persistence of Mycoplasma genitalium following azithromycin therapy.
BACKGROUND
To determine clinical outcomes and cure rates for M.genitalium genital infection in men and women following azithromycin 1 g.


METHODS
Patients attending Melbourne Sexual Health Centre between March 2005 and November 2007 with urethritis/epididymitis, cervicitis/pelvic inflammatory disease and sexual contacts of M.genitalium were tested for M.genitalium by polymerase chain reaction (PCR). M.genitalium-infection was treated with 1 g of azithromycin and a test-of-cure (toc) was performed one month post-azithromycin. Response to azithromycin, and response to moxifloxacin (400 mg daily for 10 days) in individuals with persistent infection post-azithromycin, was determined.


RESULTS
Of 1538 males and 313 females tested, 161 males (11%) and 30 females (10%) were infected with M.genitalium. A toc was available on 131 (69%) infected individuals (median = 36 days [range 12-373]). Of 120 individuals prescribed azithromycin only pre-toc, M.genitalium was eradicated in 101 (84%, 95% confidence intervals [CI]: 77-90%) and persisted in 19 (16%, 95% CI: 10-23%). Eleven individuals with persistent infection (9%, 95% CI: 5-15%) had no risk of reinfection from untreated-partners, while eight (7%, 95% CI: 3-12%) may have been at risk of reinfection from doxycycline-treated or untreated-partners. Moxifloxacin was effective in eradicating persistent infection in all cases not responding to azithromycin. Patients with persistent-M.genitalium were more likely to experience persistent symptoms (91%), compared to patients in whom M.genitalium was eradicated (17%), p<0.0001.


CONCLUSIONS
Use of azithromycin 1 g in M.genitalium-infected patients was associated with unacceptable rates of persistent infection, which was eradicated with moxifloxacin. These findings highlight the importance of follow-up in M.genitalium-infected patients prescribed azithromycin, and the need to monitor for the development of resistance. Research to determine optimal first and second-line therapeutic agents for M.genitalium is needed.
Bradshaw
Catriona S
CS
Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Victoria, Australia. cbradshaw@mshc.org.au
Chen
Marcus Y
MY
Fairley
Christopher K
CK
D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D017963:Azithromycin / Q000627:therapeutic use*; D004352:Drug Resistance, Microbial; D005260:Female; D006801:Humans; D008297:Male; D009175:Mycoplasma Infections / Q000175:diagnosis / Q000188:drug therapy* / Q000652:urine; D045704:Mycoplasma genitalium / Q000187:drug effects*; D012008:Recurrence; D012747:Sexual Partners; D017211:Treatment Failure; D014521:Urethra / Q000473:pathology; D014626:Vaginal Smears
D000900:Anti-Bacterial Agents; D017963:Azithromycin