Mycoplasma genitalium is a tiny bacteria that causes inflammation of the cervix in women, and of the urethra (penis) in men (see Diagrams – Genital System: Male and Female). It’s an STD, but unlike Gonorrhea and Chlamydia, doesn’t seem to cause rectal or oral infection. It’s fairly common as an STD, less so than Chlamydia, more so than Gonorrhea. One problem is that tests for it have become available in regular laboratories only recently (and may be expensive).
We suspect M. genitalium infection when women have vaginal discharge or Pelvic Inflammatory Disease, and tests are negative for gonorrhea and chlamydia. We’d suspect it in men with urinary symptoms and white blood cells in the urinalysis, but negative tests for STDs and urinary tract infections. It’s unsure if urine testing for the germ works in women as it does for the other STDs; it’s easy to see inflammation on the cervix and obtain a specimen from it if a pelvic exam is performed.
Antibiotic treatment for Chlamydia used to work fine for Mycoplasma, but more resistance is occurring. Now other treatments are recommended if the bacteria is found by tests, or if treatment for chlamydia was given while results were pending, but nothing showed up, and the patient still has symptoms. Unfortunately, a lot of clinicians may not have heard of the germ. Mycoplasma hasn’t been proved to cause infertility the way the other STDs can.