The World Health Organization has declared that oral sex is producing dangerous gonorrhoea and a decline in condom use is helping it to spread.
WHO warned that if someone contracts gonorrhoea, it is now much harder to treat and in some cases impossible, as the sexually transmitted infection is rapidly developing resistance to antibiotics.
The World Health Organization analysed data from 77 countries which showed that gonorrhoea's resistance to antibiotics was widespread.
About 78 million people pick up the STI each year and it can cause infertility.
The report said there are reported cases in Japan, France and Spain where the infection was completely untreatable.
It said the vast majority of gonorrhoea infections are in poor countries where resistance is harder to detect.
Gonorrhoea can infect the genitals, rectum and throat, but it is the last that is most concerning health officials.
Dr Teodora Wi, of the WHO said antibiotics could lead to bacteria in the back of the throat, including relatives of gonorrhoea, developing resistance.
She said: "When you use antibiotics to treat infections like a normal sore throat, this mixes with the Neisseria species in your throat and this results in resistance."
Thrusting gonorrhoea bacteria into this environment through oral sex can lead to super-gonorrhoea.
A decline in condom use, which had soared because of fears of HIV/Aids, is thought to help the infection spread.
The disease is caused by the bacterium called Neisseria gonorrhoea. The infection is spread by unprotected vaginal, oral and anal sex. Symptoms can include a thick green or yellow discharge from sexual organs, pain when urinating and bleeding between periods.
However, of those infected, about one in 10 heterosexual men and more than three-quarters of women, and gay men, have no easily recognisable symptoms.
Untreated infection can lead to infertility, pelvic inflammatory disease and can be passed on to a child during pregnancy.
The World Health Organization is calling on countries to monitor the spread of resistant gonorrhoea and to invest in new drugs.
