STI unknown to most people is nearly as common as chlamydia

If we asked you to name-drop the most rampant type of STI, it's highly likely that chlamydia will come to mind.

After all, between 160,000 and 200,000 chlamydia cases are diagnosed in the UK annually,

You might also suggest the likes of gonorrhoea, herpes or HPV, and you wouldn't be wrong. Cases of these conditions have been steadily prevalent in recent years.

But what if we told you there's another sexually transmitted disease that flies largely under the radar, despite around 2 per cent of the country's sexually active population receiving a diagnosis per year.

Discovered as recently as 1981, this condition is known in the medical field as Mycoplasma genitalium. Usually, however, it's given the easier-to-remember nickname 'Mgen', or just 'MG'.

Apparently, it's almost as common as chlamydia (Getty Stock Images)

It's a bacterial infection that affects the urethra, cervix and sometimes the rectum.

Scientists believe Mgen is mostly contracted through unprotected vaginal or anal sex with an infected person, and research is ongoing with regard to the possibility of oral sex also allowing it to spread.

Its most common symptoms, which usually appear three weeks after infection, include pain or burning while urinating, unusual vaginal or penile discharge, pelvic discomfort, bleeding after sex, testicular pain, itching down below and inflammation in the rectum.

A reliable test for the condition was only produced less than 10 years ago, in 2017, 90 years after chlamydia was first discovered.

Despite affecting over 500,000 Brits per year, however, a minuscule 15 per cent of UK residents have actually heard of Mgen.

Mgen affects over 500,000 Brits per year (Getty Stock Images)

According to Female Health Doctor Clinic founder, Dr Nikki Ramskill, this is likely because Mgen's symptoms are largely ambiguous and often fall under the umbrella of other medical issues.

"The tricky part is that these symptoms look very similar to other common STIs," she explained.

Like HPV, Mgen is also resistant to antibiotics commonly used to treat other STIs.

"Mgen isn’t included in standard STI screening unless there’s a specific reason, like persistent symptoms," Dr Ramskill continued. "Widespread testing could lead to unnecessary antibiotic use, which is a real concern given how resistant this infection already is."

She added: "In women, 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.

Two types of antibiotics are usually prescribed (Getty Stock Images)

"It’s not something to ignore if symptoms are ongoing."

Despite being resistant to antibiotics, Mgen patients can still receive treatment.

Superdrug Online Doctor, Babak Ashrafi, explained: "In some regions, resistance rates exceed 90%, making MG one of the fastest-growing antibiotic-resistant STIs.

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