Quinolone-resistant gonorrhea increases in Ontario

The prevalence of quinolone-resistant gonorrhea has increased rapidly in Ontario - Canada's most populous province - from a rate of 2% in 2001 to 28% in 2006, found a study published in CMAJ.

Infections in heterosexual men appear to have contributed to the increased rate of resistance.

Other studies have associated quinolone-resistant gonorrhea with men having sex with men, antibiotic use, over 35 years of age and travel to Asia.

"The magnitude of the rate of resistance to quinolone in Ontario is unusually high by any threshold reported in North America," state Dr. Susan Richardson from The Hospital for Sick Children (SickKids) and coauthors. "Given Ontario's large population and its status as a major economic centre and national transit hub, its epidemiology is likely to influence epidemiological trends in other provinces of Canada."

After several years of declining infection rates, Neisseria gonorrhoeae infections are on the rise in Canada and many other countries, with health ramifications as the disease can cause infertility and serious blood, joint and immune complications.

The study findings underscore the current recommendations in Canada not to use quinolones for treatment of N. gonorrhoeae infections. Ongoing testing for antibiotic resistance is necessary, although new testing methods are replacing methods that test for susceptibility. "The importance of using culture diagnostics for N. gonorrhoeae needs to be communicated to clinicians, laboratories and public health organizations," conclude the authors.

In a related commentary http://www.cmaj.ca/press/pg268.pdf, Dr. John Tapsall from Prince of Wales Hospital in Sydney, Australia states "in developed countries, the spread of quinolone-resistant N. gonorrhoeae infection has followed a pattern in which different resistant subtypes are imported, sometimes over many years. The subtypes are eventually introduced into a country's sexual networks and then achieve sustained endemic transmission."

Appropriate antibiotic use is crucial for controlling drug-resistance in community-acquired pathogens. A sustained global approach is needed to reduce the rates of drug-resistant gonorrhea and to control the disease. All countries are at risk of the spread of even more resistant strains of this highly adaptable pathogen.