"Doctors have expressed 'huge concern' that super-gonorrhoea has spread widely across England," BBC News reports.
Public Health England issued the warning about the rise of a strain of gonorrhoea that has developed resistance to a widely used antibiotic.
Gonorrhoea is a sexually transmitted infection (STI) caused by bacteria called Neisseria gonorrhoeae or gonococcus. It used to be known as "the clap".
The bacteria are mainly found in discharge from the penis and vaginal fluid.
It is easily passed between people through:
Typical symptoms of gonorrhoea include a thick green or yellow discharge from the vagina or penis, pain when urinating, and bleeding between periods in women.
However, around 1 in 10 infected men and almost half of infected women don't experience any symptoms.
The infection can also be passed from a pregnant woman to her baby. If you're pregnant and may have gonorrhoea, it's important to get tested and treated before your baby is born. Without treatment, gonorrhoea can cause permanent blindness in a newborn baby.
Super-gonorrhoea is a term used to describe strains of gonorrhoea that have developed a resistance against the antibiotic normally used to treat the infection – azithromycin. There is an alternative antibiotic called ceftriaxone, which is also effective.
But there are concerns that strains could also develop resistance to ceftriaxone, which would make the disease extremely challenging to treat.
Dr Gwenda Hughes, consultant scientist and head of the STI section at Public Health England, explained: "We know that the bacterium that causes gonorrhoea can rapidly develop resistance to other antibiotics that are used for treatment, so we cannot afford to be complacent.
"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."
An outbreak of cases was first reported in Leeds in November 2014.
Additional cases have now been confirmed in the West Midlands and the south of England, five of which were in London.
This takes the total number of cases confirmed in England from November 2014 to April 2016 up to 34.
Cases have been reported both in heterosexual couples and men who have sex with men.
Dr Hughes advises that, "Everyone can significantly reduce their risk by using condoms with all new and casual partners."
Getting tested for STIs regularly can lead to early identification and treatment, as often these infections have no symptoms.
In addition, reducing the number of sexual partners you have and avoiding overlapping sexual relationships can reduce the risk of becoming infected.
If you have put yourself at risk of any STI, it is always best to seek advice from your local sexual health clinic.