A man who lives in the United Kingdom has contracted a strain of gonorrhea that has the highest level of resistance to antibiotics seen to date, Medscape reports.

In recent years, public health officials around the globe have increasingly warned about the possibility that strains of gonorrhea may soon begin to circulate that are resistant to the only recommended antibiotic treatment for the sexually transmitted infection (STI), a combination of azithromycin and ceftriaxone.

According to Public Health England, the man in question likely contracted this strain of gonorrhea from sexual contact with a woman while traveling in Southeast Asia. The sexual encounter occurred one month before he developed symptoms, for which he sought sexual health services back in the United Kingdom. He had a sexual encounter with one woman since returning to his home country; she has thus far tested negative for the STI.

The man’s infection displayed high-level resistance to azithromycin and resistance to ceftriaxone. He is now being treated with intravenous ertapenem, an antibiotic that is considered a last resort for treating drug-resistant gonorrhea. Signs indicate that this treatment will prove effective, but at this point, more time is needed to declare success in clearing the STI.

In a press release, the British Association for Sexual Health and HIV expressed “deep concern” over the case.

Gonorrhea has developed resistance to all antibiotics ever used to treat the STI.

To read the statement from the British Association for Sexual Health and HIV on the gonorrhea strain, click here.

To read the Medscape article, click here (free registration with the site is required).