Drug-resistant strains of gonorrhoea have spread to countries across the world, the UN 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" gonorrhoea strain in Japan that is resistant to all recommended antibiotics and warned then that it could transform a once easily treatable infection into a global health threat.

The World Health Organisation (WHO) said those fears are now reality, with many more countries around the world, 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.     

"We are very concerned about recent reports of treatment failure from the last effective treatment option - the class of cephalosporin antibiotics," she added. "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 (CDC), the number of cases is estimated at around 700,000 a year.     

The WHO called for greater vigilance on the correct use of antibiotics and more research into alternative treatments for so-called gonococcal infections.     

The emergence of drug-resistant or superbug strains of gonorrhoea is caused by unregulated access to and overuse of antibiotics, which helps fuel natural genetic mutations within the bacteria.         

Experts say an added problem with gonorrhoea is that its strains tend to retain their genetic resistance to previous antibiotics even after their use has been discontinued.

The United Nations' health agency said it does not yet how far or wide drug resistance in gonorrhoea has spread, as many countries lack reliable data. But it put the number of people who have contracted it in the millions.     

"The available data only shows the tip of the iceberg," said Lusti-Narasimhan. "Without adequate surveillance we won't know the extent of resistance to gonorrhoea and without research into new antimicrobial agents, there could soon be no effective treatment for patients."         

Experts say the best way to reduce the risk of even greater resistance developing - beyond the urgent need to develop effective new drugs - is to treat gonorrhoea with combinations of two or more types of antibiotic at the same time.     

This technique is used in the treatment of some other infections like tuberculosis in an attempt to make it more difficult for the bacteria to learn how to conquer the drugs.     

Gonorrhoea can be prevented through safer sexual intercourse. The WHO said early detection and prompt treatment, including of sexual partners, is essential to control sexually transmitted infections. – Reuters