Senior medics have raised concerns about running out of treatments for a highly-resistant strain of “super-gonorrhoea” that has spread across parts of the UK.
Public health watchdogs warned a powerful form of the sexually transmitted disease had been found in the West Midlands and South-East England, despite attempts to curb a major outbreak in the north of England last year.
The strain is resistant to an antibiotic called azithromycin so doctors are having to rely on a second drug, ceftriaxone, to treat it.
There are no other effective drugs to tackle the strain, sparking fears it could become untreatable if it builds up further resistance.
Chancellor George Osborne warned last week that antibiotic resistance could become a greater threat to humanity than cancer, if it continues unchecked.
Scots public health leaders are monitoring the outbreak and people are urged to use condoms with new partners to reduce the risk of catching the disease, which can lead to infertility or severe complications if untreated.
Dr Gwenda Hughes, of Public Health England, which published the warning, said: “If strains of gonorrhoea emerge that are resistant to both azithromycin and ceftriaxone treatment options would be limited as there is currently no new antibiotic available to treat the infection.”
There have been 34 confirmed cases since November 2014, she said.
Hugh Pennington, emeritus professor in bacteriology at Aberdeen University, said the resistant strain was a major public health concern across the UK as doctors were running out of treatment options.
He said: “Gonorrhoea is the one bug I am most concerned about as it is very difficult to treat using anything other than antibiotics.
“Antibiotics have been the mainstay of treatment for patients but not for much longer. We are now on the edge of some quite hard times.”
It is harder to prevent the spread of sexually transmitted superbugs than hospital acquired infections, he added.