Drug-resistant strains of gonorrhoea have spread to countries across the world, the United Nations health agency said on Wednesday, and millions of patients may run out of treatment options unless doctors catch and treat cases earlier. Scientists reported last year finding a "superbug" strain of gonorrhoea in Japan in 2008 that was resistant to all recommended antibiotics and warned then that it could transform a once easily treatable infections into a global health threat. The World Health Organization said those fears are now reality with many more countries, including Australia, France, Norway, Sweden and Britain, reporting cases of the sexually transmitted disease resistant to cephalosporin antibiotics - normally the last option for drugs against gonorrhoea. "Gonorrhoea is becoming a major public health challenge," said Manjula Lusti-Narasimhan, from the WHO's department of reproductive health and research. She said more than 106 million people are newly infected with the disease every year. The organism is what we term a superbug - it has developed resistance to virtually every class of antibiotics that exists," she told a briefing in Geneva. "If gonococcal infections become untreatable, the health implications are significant." Gonorrhoea is a bacterial sexually transmitted infection which, if left untreated, can lead to pelvic inflammatory disease, ectopic pregnancy, stillbirths, severe eye infections in babies, and infertility in both men and women. It is one of the most common sexually transmitted diseases in the world and is most prevalent in south and southeast Asia and sub-Saharan Africa. In the United States alone, according to the Centers for Disease Control and Prevention, the number of cases is estimated at around 700,000 a year.The WHO said it is not yet clear how far or wide drug resistance in gonorrhoea has spread, as many countries lack reliable data.