Study of Time to Eradication of Mycoplasma Genitalium and Chlamydia Trachomatis After Antibiotic Treatment

Mycoplasma genitalium (Mg), detected in 1980, causes a urogenital infection through sexual transmission. In contrast to Chlamydia trachomatis antibiotic resistance is common against tetracyclines and is emerging against macrolides such as azithromycin. Both antibiotics are recommended as the first line treatment of chlamydia infection. Recent published data, however, indicate that 1g azithromycin stat may be only bacteriostatic when treating chlamydia. The consensus to date is that there should always be a test of cure in pregnant women having been treated for chlamydia and in all individuals treated for Mg. There are no studies published, to our knowledge, where the time to eradication after antibiotic treatment commenced in Mg infection has been evaluated. The first line treatment of a confirmed Mg infection is azithromycin 1.5 g given during a period of 5 days. If macrolide resistance is plausible or confirmed moxifloxacin 400mg for 7 to 10 days is recommended. Individuals with symptomatic urethritis or cervicitis and/or being sexual partners to individuals being treated for a suspect or confirmed Mg or CT infection were eligible. The study subjects were patients attending either of the STD-clinics in Norrköping or Västervik, Sweden. All samples were sent to Statens Serum Institut(SSI), Mycoplasma department (Jorgen Skov Jensen) for analysis. Patients accepting enrolment with a confirmed or highly suspected Mg were receiving azithromycin 500 mg the first day and 250mg the following four days. Patients where macrolide resistant Mg-strain infection was highly suspected received moxifloxacin 400 mg once daily for seven days. Those subjects intended to treatment but with a lower degree of suspicion of Mg infection were randomized to either a treatment with doxycycline 200 mg the first day and 100 mg once daily the following nine days (the custom and recommendation in Sweden for treatment of chlamydia and non-specific urethritis or cervicitis) OR a treatment with azithromycin 1g as a single dose. All participants were given test kits for 12 samples, which were to be sampled three times weekly (every second day) during four weeks starting the day after the first day of treatment. They were instructed not to have any sexual intercourse during the first week and with condom afterwards during the study period. The samples were to be sent once weekly (three samples)to SSI.The date of sampling was to be noted on the label of the tube and the attaching paper to SSI, where also any symptoms were to be noted. The results of the tests were sent to the STD-clinic who informed the patient. The study started in February 2010 and inclusion of patients have ended for those subjects with a verified M genitalium infection (February 2014), whereas patients with a verified or suspected chlamydia infection still are enrolled and randomised to azithromycin 1 g or doxycycline. A manuscript will soon be submitted concerning those subjects being treated for a M genitalium infection. To date 190 patients have been enrolled and also fulfilled the study protocol with sampling of specimens.