THOUSANDS of people in Dorset could be carrying a new sexually transmitted ‘superbug’ which can leave women infertile.

Mycoplasma genitalium, known as MG, affects between one and two per cent of the population, according to the British Association of Sexual Health and HIV.

But it can cause no symptoms and tests to diagnose it are not routinely available, and the association claims the spread of the disease as a “public health emergency waiting to happen”.

Medicines for chlamydia are ineffective against MG, and could cause it to develop antibiotic resistance.

Association expert Paddy Horner said: "MG is treated with antibiotics, but as until recently there has been no commercially available test it has often been misdiagnosed as chlamydia and treated as such.

"This is not curing the infection and is causing antimicrobial resistance in MG patients.

"If practices do not change and the tests are not used, MG has the potential to become a superbug within a decade, resistant to standard antibiotics.

"The greatest consequence of this is for the women who present with pelvic inflammatory disease caused by MG, which would be very hard to treat, putting them at increased risk of infertility."

Data from Public Health England shows that 962 people in Bournemouth, 394 in Poole and 799 in Dorset were diagnosed with chlamydia last year alone.

But this accounts for less than 0.5 per cent of adults in the area, meaning that statistically many cases of MG or chlamydia are likely to be undiagnosed. Fewer than a quarter of adults in the county aged between 15 and 24, among whom chlamydia is most easily spread, were screened for the disease in 2017.

New guidelines on how to tackle MG have been accredited this month by the National Institute for Health and Care Excellence.

They recommend the introduction of an accurate MG test.

Dr Horner, who developed the guidelines, said: "These new guidelines have been developed because we can’t afford to continue with the approach we have followed for the past 15 years, as this will undoubtedly lead to a public health emergency with the emergence of MG as a superbug."

The association said that seven in every 10 sexual health experts across the country said they were not able to afford the diagnostic tests recommended by the guidelines, leading to concerns the disease will be mistreated.

Its has called on the Government to make more funding available to sexual health clinics to tackle the disease.

The new guidelines come two months after a British man was reported to have the “world’s worst case" of super-gonorrhoea.

Like MG, it also proved resistant to antibiotics.

MG is lower profile then gonorrhoea, but more widespread. Last year, in Dorset, 231 people were diagnosed with gonorrhoea.