Everything you need to know about Mgen — the STI you might not have heard about

Do you know about the sexually transmitted infection Mycoplasma genitalium (Mgen)? There’s a good chance you don’t. This is despite a 2018 survey concluding around 1.7% of people aged 18-59 in the US carry the bacteria.

Among men turning up at STI clinics with urethritis, 28.7% were positive for Mgen. Urethritis is an infection of the tube that you pee through.

It affects all genders. In gay and bisexual men, it’s more likely to be present in your urethra or rectum than in your throat.

A recent British survey found that 85% of those questioned had not heard of Mgen.

“Mgen is considered a ‘new’ STI. It was only discovered in 1981 and a reliable test for it only became available in 2017,” says Dr Neel Patel, a GP with the LloydsPharmacy Online Doctor service.

“It can be spread by both vaginal and anal sex, although transmission may occur even without penetration.”

The bacterial infection is of increasing concern to the Centers for Disease Control (CDC) because antibiotic-resistant strains have emerged. The CDC now asks healthcare providers to alert them if they find cases that don’t respond to the usual medication.

Symptoms of Mgen

Symptoms of Mgen include pain or a burning sensation when peeing, itching, or a discharge from your penis. Often there are no symptoms.

It’s unknown if men with Mgen who have no symptoms face long-term consequences. In women, Mgen has been associated with pelvic inflammatory disease, although a direct link is unclear. The infection can sometimes clear up on its own.

So why have you probably never heard of this infection?

Well, as many people have symptomless Mgen, and it poses fewer long-term health risks, it’s not prioritized like other STIs. You may have already had it and never even realized.

Also, STI clinics do not routinely test for the infection. Although it’s relatively easy to identify infections such as gonorrhea, Mgen requires a more complicated form of analysis. This is known as nucleic acid amplification testing (NAAT).

The CDC notes, “Mgen is an extremely slow-growing organism. Culture can take up to six months and only a few research settings in the U.S. have the technical capability to culture Mgen.”

Clinics will routinely test you for HIV, syphilis, gonorrhea and chlamydia. If you test negative for these but still have symptoms, you will be told you have NGU or NSU (Non-Gonococcal or Non-Specific Urethritis). These are umbrella terms that include Mgen.

If you have NGU, you will receive a broad-acting antibiotic and this will probably sort out the problem.

However, as we say, there’s been an increase in strains of Mgen resistant to the usual drugs. The CDC is now advising clinics to think about offering Mgen testing for people who turn up with persistent urethritis that doesn’t clear up after taking medication.

If you’re sexually active, there’s little you can do to avoid Mgen. Wearing a condom and reducing your number of sexual partners will reduce the risk of acquiring it.

“An incredibly frustrating STI”

Dr Carlton Thomas is a gay doctor with a large online following. He told Queerty that he advised men to ask about Mgen testing if they have symptoms but test negative for the usual STIs, “or if they have persistent symptoms after STI treatment.

“NGU can be an incredibly frustrating STI as it often isn’t suspected at first in clinics and has a tricky resistance pattern. There is no US-based pure screening recommendation for Mgen, so we often don’t routinely check for it unless someone has documented exposure.

“Due to the expense of NAAT testing and resistance testing, it is often only checked when a patient has urethritis symptoms (burning or urethral discharge) with a negative test for other common STIs or has persistent symptoms despite treatment for gonorrhea or chlamydia.”

Carlton says one of his Instagram followers received an Mgen diagnosis, but only after nine months of persistent symptoms.

“He went to the urgent care with sensitivity when he would go pee. He got tested for gonorrhea and chlamydia and was given the typical meds, but the test would always come back negative, and his symptoms would persist.

“Finally, he went back after multiple trips to the urgent care and one of the newer doctors there suggested it could be mycoplasma, so he was given the second portion of the treatment because he had just finished the typical first portion of the treatment for chlamydia. His symptoms went away immediately,” says Dr Thomas.

“Mgen is becoming a bigger problem and something to consider when testing!”