Diagnosis and Treatment of Mycoplasma Genitalium

Mycoplasma genitalium (MG), has only recently started to be recognized as a significant health concern. It is a relatively common bacteria discovered in the 1980s which were once thought to be harmless, effectively "hitching a ride" on the back of other diseases rather than causing disease on its own.

These days, that's no longer true. MG is considered a significant cause of sexually transmitted infections (STIs) with scientists only just beginning to give it the full attention it deserves.

Understanding Mycoplasma Genitalium

It is now clear that Mycoplasma genitalium is the prime rather than secondary cause of many infections, including forms of bacterial vaginosis (BV) and non-gonococcal urethritis (NGU). It has also been associated with pelvic inflammatory disease (PID) and implication in other infections once attributed to other bacteria.

By and large, most cases of MB are asymptomatic. If symptoms do appear, they are largely nonspecific and easily mistaken for other STIs such as chlamydia and gonorrhea. They also differ significantly in women and men:

Women tend to experience vaginal itching, burning on urination, and pain during intercourse. MG is also associated with bacterial vaginosis, the symptoms of which can include a fishy odor after sex and changes in vaginal discharge.
Men, on the other hand, may experience urethral discharge, burning on urination, and pain and swelling of the joints (arthritis). MG is the most common cause of non-chlamydial non-gonococcal urethritis in men.

Challenges in Diagnosing Mycoplasma Genitalium

The main barrier to diagnosing MG is that there is no approved blood test to confirm infection. Direct diagnosis requires a bacterial culture which takes up to six months to grow. There are other ways to identify it, but those tests are mostly reserved for research.

Because of this, MG is usually diagnosed a presumptively. In other words, a doctor will assume MT is the cause after extensively ruling out all other options.

To most experienced clinicians today, MG is generally assumed to be involved in both BV and NGU infections. According to the Centers for Disease Control and Prevention, 15 to 20 people of NGOs are directly caused by MG. MG is also implicated in one of three cases of persistent or recurrent urethritis.

Challenges in Diagnosing Mycoplasma Genitalium

Mycoplasma genitalium is standardly treated with antibiotics, most commonly a single 1g dose of azithromycin. While azithromycin is considered safe and effective, there is now evidence of increasing resistance to the drug in populations where it broadly used.

While other antibiotics may be substituted, doxycycline is considered less effective (albeit with a lower risk of resistance) while moxifloxacin offers good action but carries a risk of resistance, as well.

This highlights a growing problem with the syndromic treatment of STIs (treating a class of diseases in the same way). It presumptively exposes a person to medications that may not work as well or effectively. In the event of a bacterial infection, this can add to the already huge problem of antibiotic resistant bacteria (as seen with diseases such as gonorrhea).

This is why the development of a definitive blood test to confirm MG infection remains so important.