A strain of gonorrhea is that is resistant to all currently available antibiotics has been identified in Japan.

Gonorrhea is a bacterial infection that can be transmitted through oral, genital or anal sex with an infected person. If left untreated, the disease can cause other problems, including sterility and a greater susceptibility to HIV.

The newly identified strain of the sexually transmitted infection, called H041, is resistant to the last remaining drugs that treat gonorrhea, known as cephalosporin-class antibiotics, researchers told the International Society for Sexually Transmitted Disease Research conference in Quebec City this week.

"This was found in Kyoto in Japan," said Magnus Unemo of the Swedish Reference Laboratory for Pathogenic Neisseria, who presented the findings.

"This was unfortunately a female commercial sex worker, which is also very worrisome because if it is already in that type of risk group, [there is] a fear that it can spread more rapidly."

The new strain has genetic mutations that make it resistant to cephalosporin antibiotics, tests of Japanese samples showed.

None found in Canada, U.S.

Gonorrhea infection can cause the hand and wrist to swell if it spreads through the bloodstream and leads to a widespread reaction. Courtesy of Susan Lindsley/CDC

In Canada, the Public Health Agency of Canada said it monitors antibiotic resistance in gonorrhea in collaboration with provincial and territorial authorities.

"This specific strain of gonorrhea has not been identified in Canada," the agency said in an email.

Reported cases of gonorrhea decreased slightly between 2008 and 2009, the latest year for which Canadian figures are available. The rate of reported infections jumped by almost 65 per cent overall from 2000 — up by 95 per cent in females and by 46 per cent in males, PHAC said.

The rate of reported infections was 33 per 100,000 population in 2009.

"It heralds really an era of non-treatable gonorrhea, and so in that sense it's very concerning for us, " said Dr. Vanessa Allen, a medical microbiologist at the Ontario Agency for Health Protection and Promotion.

In the pre-antibiotic era, gonorrhea infections were associated with infertility and infections in newborns that can lead to blindness.

The long-term solution is to invest in the development of new drugs and to look for gonorrhea infections more aggressively, suggested Allen, who is attending the conference.

'Be vigilant'

One reason gonorrhea could be so difficult to eliminate, Allen said, is that safe sex practices haven't been widely adopted for oral sex, said Dr. Vanessa Allen. CBC

On Friday, investigators at the U.S. Centers for Disease Control and Prevention also reported that gonorrhea is becoming more resistant to cephalosporin.

The decade-long analysis looked at almost 6,000 gonorrhea samples from men in 30 U.S. cities from January 2000 to June 2010.

The tests measured the minimum inhibitory concentrations — the lowest concentration of antibiotics needed to stop growth of bacteria in the lab.

From 2000 to 2010, the percentage of isolates showed higher minimum inhibitor concentrations rose from 0.2 per cent to 1.4 per cent for an oral cephalosporin and from 0.1 per cent to 0.3 per cent for an injectable form of the antibiotic.

"Although cephalosporins remain an effective treatment for gonococcal infections, health-care providers should be vigilant for treatment failure and are requested to report its occurrence to state and local health departments," Dr. Robert Kirkcaldy of the CDC and his co-authors said.

One of reasons gonorrhea could be so difficult to eliminate, Allen said, is that safe sex practices haven't been widely adopted for oral sex. Gonorrhea in the pharynx is very difficult to treat with antibiotics, she said.

To date, there are no recorded cases of patients with gonorrhea that couldn't be treated with these antibiotics in the United States.

The study was published in the July 8 edition of the CDC's Morbidity and Mortality Weekly Report.

With files from CBC's Kelly Crowe