A potentially dangerous sexually transmitted disease that infects millions of people each year is growing resistant to drugs.

It could soon become untreatable, the World Health Organization said.

The U.N. health agency is urging governments and doctors to step up surveillance of antibiotic-resistant gonorrhea, a bacterial infection that can cause inflammation, infertility, pregnancy complications and, in extreme cases, lead to maternal death. Babies born to mothers with gonorrhea have a 50 percent chance of developing eye infections that can result in blindness.

"This organism has basically been developing resistance against every medication we've thrown at it," said Dr. Manjula Lusti-Narasimhan, a scientist in the agency's department of sexually transmitted diseases. This includes a group of antibiotics called cephalosporins currently considered the last line of treatment.

"In a couple of years it will have become resistant to every treatment option we have available now," she told The Associated Press in an interview ahead of WHO's public announcement on its 'global action plan' to combat the disease.

Lusti-Narasimhan said the new guidance is aimed at ending complacency about gonorrhea and encouraging researchers to speed up their hunt for a new cure.

Once considered a scourge of sailors and soldiers, gonorrhea - known colloquially as the clap - became easily treatable with the discovery of penicillin. Now, it is again the second most common sexually transmitted infection after chlamydia. The global health body estimates that of the 498 million new cases of curable sexually transmitted infections worldwide, gonorrhea is responsible for some 106 million infections annually. It also increases the chances of infection with other diseases, such as HIV.

"It's not a European problem or an African problem, it's really a worldwide problem," said Lusti-Narasimhan.

Scientists believe overuse or incorrect use of antibiotics, coupled with the gonorrhea bacteria's astonishing ability to adapt, means the disease is now close to becoming a super bug.

Bacteria that survive antibiotic treatment due to a mutation that makes them resistant then quickly spread their genes in an accelerated process of natural selection. This is a general problem affecting all antibiotics, but gonorrhea is particularly quick to adapt, said Lusti-Narasimhan.

"If it didn't do so much damage it would actually be a fun organism to study," she said.

Resistance to cephalosporins was first reported in Japan, but more recently has also been detected in Britain, Australia, France, Sweden and Norway. As these are all countries with well-developed health systems, it is likely that cephalosporin-resistant strains are also circulating undetected elsewhere.

Therefore the Geneva-based agency wants countries not just to tighten their rules for antibiotic use, but also to improve their surveillance systems so that the full extent of the problem can be determined.

Better sex education is also needed, as proper condom use is an effective means of stopping transmission, said Lusti-Narasimhan.

"We're not going to be able to get rid of it completely," she said. "But we can limit the spread."