STI that less than 15 percent of people have heard of is resistant to antibiotics

The most commonly mentioned sexually transmitted infections (STIs) include the likes of chlamydia, HPV (genital warts), gonorrhea, herpes and syphilis.

But another with a similar infection rate to chlamydia has gone largely under the radar and was only discovered in 1981.

LloydsPharmacy Online Doctor says only 15 percent of Brits have heard of Mycoplasma genitalium (Mgen), and that it affects approximately two percent of the population.

Mgen 'is an STI that can cause infection among people who are sexually active' and can 'infect the cervix, inside the penis, or the rectum', according to the Centers for Disease Control and Prevention (CDC).

"Sexually active people can get Mgen by having vaginal or anal sex without a condom with someone who has the infection. Researchers are still determining whether sex partners can spread Mgen through oral sex," the health organisation said.

They note that a 'person with Mgen can pass the infection to someone even when they have no signs or symptoms'.

Data shows a 74 percent rise in diagnoses between 2021 and 2023 (Getty Stock Images)

Mgen symptoms

• Vaginal discharge
• A burning sensation when peeing
• Discharge from the penis
• Genital itching
• Bleeding after sex
• Inflammation in the rectum

Many people, particularly men, may have no symptoms at all (Getty Stock Images)

Why Mgen is less known

Dr Nikki Ramskill explained to Metro that while it 'behaves a bit like chlamydia, it’s less well known and harder to treat'.

The founder of The Female Health Doctor Clinic warned that 'Mgen isn’t included in standard STI screening unless there’s a specific reason, like specific symptoms'.

Tests were only made widely available after 2017.

"Widespread testing could lead to unnecessary antibiotic use, which is a real concern given how resistant this infection already is," Dr Ramskill added.

Mgen is slightly more common in women than men

The disease is often symptomless for 50 to 70 percent of women, and 80 percent of men, according to the British Association of Sexual Health.

Dr Babak Ashrafi told the outlet that more than half of Brits are having unprotected sex and 'not having been tested for STIs like gonorrhoea, it’s a concern'.

It's curable with a course of specific antibiotics (Getty Stock Images)

"In men, it’s linked to epididymitis (where a tube behind the testicles becomes swollen and painful) and proctitis (inflammation in your rectum).

"Treatment now usually requires a two-stage antibiotic approach, typically doxycycline followed by azithromycin or moxifloxacin."

"Untreated Mgen can cause serious complications," the Superdrug Online Doctor warned, adding that 'in some regions, resistance rates exceed 90 percent, making Mgen one of the fastest-growing antibiotic-resistant STIs'.

Dr Ramskill also said that the danger for women is that 'it can lead to cervicitis (inflammation of the cervix) and pelvic inflammatory disease (PID), which in some cases may affect fertility and cause spotting in between periods'.

The advice is to wear a condom and to get tested if you have symptoms.