Hearing you have any kind of sexually transmitted disease is bad news, but the most dreaded ones are those that have no cure. Living with HIV or herpes for the rest of your life is very different than an unfortunate case of chlamydia or gonorrhea which, while painful, can be cleared up with common antibiotics. That is, until super-gonorrhea.

According to the BBC, doctors have expressed “huge concern” that a strain of drug-resistant gonorrhea has been spreading across the United Kingdom. The strain prompted a national alert when it popped up last year in Leeds, and now there is increased risk the disease could become untreatable.

Super-gonorrhea started by affecting straight couples, but doctors are seeing it in gay men too. Public Health England stated that attempts to contain the outbreak in West Midlands, London, and southern England have had only “limited success.”

Two drugs, azithromycin and ceftriaxone, are used in combination to cure gonorrhea, but now that resistance to azithromycin is spreading, doctors fear ceftriaxone will soon become ineffective as well. Gonorrhea, which is transmitted through vaginal, oral, and anal sex, can lead to infertility if left untreated, and can even be passed on to a child during pregnancy. The infection can easily go unnoticed — when infected, more than 75 percent of women and gay men have no easily recognizable symptoms, as do one in 10 heterosexual men. Experts say the biggest issue with super-gonorrhea passing to gay men is the rate of transfer.

“We’ve been worried it would spread to men who have sex with men,” Peter Greenhouse, a Bristol consultant in sexual health, told BBC. “The problem is [they] tend to spread infections a lot faster simply as they change partners more quickly.”

In addition, men who have sex with men are more likely to develop the infection in their throats, where there is other bacteria that can share resistance to drugs, and where antibiotics reach in lower doses.

Public Health England warned that the growing rate of super-gonorrhea cases is a “further sign of the very real threat of antibiotic resistance to our ability to treat infections,” and Chancellor George Osbourne said that antibiotic resistance would become “an even greater threat to mankind than cancer” if global action was not taken.

Antibiotic resistance is a problem for infectious diseases of all kinds. Thanks to antibiotics in meat and overprescription, many types of bacteria are now shrugging off our most powerful drugs. In the case of super-gonorrhea, experts are urging vigilance and safe sex.

“We cannot afford to be complacent,” said Dr. Gwenda Hughes, the head of the sexually transmitted infections unit at Public Health England. “If strains of gonorrhea emerge that are resistant to both azithromycin and ceftriaxone, treatment options could be limited as there is currently no new antibiotic available to treat the infection.”

Public Health England is trying to find sexual partners of people who have been diagnosed with the superbug. Worryingly, a little less than half of reported sexual partners reported successfully followed up with the agency, but 94 percent of those tested had the infection.