Patients are frequently concerned about the risk of having contracted a sexually transmitted disease. Should GPs be routinely investigating asymptomatic patients for Mycoplasma genitalium?
Non-specific urethritis (NSU) is infection of the urethra (and typically, also the cervix in women) that is not caused by gonococcus or chlamydia. NSU usually refers to infection with Ureaplasma urealyticum (this is considered to be normal genital flora) and Mycoplasma genitalium, although other causes include trichomonas and viruses, such as herpes. NSU is most commonly diagnosed in men, as the symptoms are more easily missed in women. Symptoms, if present, include dysuria, a watery or mucoid discharge, dyspareunia, abnormal vaginal bleeding and pain in the testicles or epididymis. Complications of Mycoplasma genitalium include pelvic inflammatory disease, epididymo-orchitis, proctitis and preterm labour.
The diagnosis may be made on microscopy or by nucleic acid amplification testing of endocervical or urethral swabs or from the first part of the first urine passed in the morning. However, should asymptomatic patients be tested for Mycoplasma genitalium or Ureaplasma urealyticum? The answer, according to the Australian STI Management Guidelines (for use primary care) is currently NO. In particular, Ureaplasma is normally found in the genital tract. Testing should be limited to patients who are symptomatic and those who have been in contact with individuals diagnosed with the condition.
Good medicine includes the treatment (with azithromycin 1g stat po) of patients who have symptoms that could be due to chlamydia or NSU. This is even if they have tested negative for chlamydia (note that they should then be investigated for Mycoplasma). This treatment will work in approximately 60% of symptomatic patients who have Mycoplasma genitalium, however the remaining 40% should have further treatment if testing is positive and specialist opinion may be advisable. Extended courses of azithromycin have not been shown to increase cure rates, and resistance to macrolides now occurs in approximately 30% of cases of Mycoplasma genitalium.
Sexual contact should be avoided for seven days after treatment and the patient should avoid sexual activity with any partners they have had in the last six months, unless these individuals have been tested and, if necessary, treated. It therefore follows that contacts should be traced back for six months, or greater in certain situations.
After at least two weeks post-treatment, the test should be repeated to ensure a negative result has been obtained. This should be repeated at three months, along with other sexually transmitted disease screening, if desired. Mycoplasma genitalium is not a notifiable disease.
Australian STI Management Guidelines (for use primary care) updated May 2016 Australasian Sexual Health Alliance