A UK man is believed to have caught the first ever case of antibiotic-resistant gonorrhoea while on holiday in south-east Asia.
The BBC reports the man had travelled to Asia from the UK and caught the bug from sexual activity with a woman while abroad. He had a partner at home in the UK when he caught the disease.
The usual treatment for gonorrhoea - a combination of theazithromycin and ceftriaxone antibiotics - has been unable to fight off the bug.
"This is the first time a case has displayed such high-level resistance to both of these drugs and to most other commonly used antibiotics," Public Health England's Dr Gwenda Hughes told BBC News.
"We are following up this case to ensure that the infection was effectively treated with other options and the risk of any onward transmission is minimised."
The man is now being treated intravenously with the antibiotic ertapenem, and doctors say he has shown some improvement - although the results won't be known for at least a month.
Without treatment, gonorrhoea can cause infertility and spread to joints or heart valves.