March, 29, 2018 -- The world's "worst-ever" case of super-gonorrhea has been diagnosed in a U.K. man who was infected after sex with a woman in south-east Asia, health officials say.

It's the first case of the sexually-transmitted disease that could not be cured with the main antibiotic treatment, a combination of azithromycin and ceftriaxone, according to Public Health England, BBC News reported.

The unidentified man picked up the superbug earlier this year and health officials are trying to track down his other sexual partners in an effort to contain the spread of the disease.

"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," said Dr. Gwenda Hughes, Public Health England, BBC News reported.

The World Health Organization and the European Centers for Disease Control confirm that this is the first such case in the world, BBC News reported.

Experts worry that this superbug could eventually become resistant to all antibiotics.

"The emergence of this new strain of highly resistant gonorrhea is of huge concern and is a significant development," Olwen Williams, president of the British Association for Sexual Health and HIV, told BBC News.