Other Infections

CDC Warns of Resistant Gonorrhea; First 'Superbug' Found

A week after a CDC report warning that gonorrhea appears to be developing resistance to the last remaining class of effective antibiotics, researchers detected the first extensively resistant strain in Japan.

Resistance to antibiotics is a growing public health concern. Resistance can arise through poor adherence, failure to finish a full course of therapy, or excessive use of the drugs for purposes other than medical treatment. Neisseria gonorrhoeae, which causes gonorrhea, is among the pathogens that has developed resistance to multiple types of antibiotics. Gonorrhea can cause genital symptoms such as pain and discharge, and in women may progress to pelvic inflammatory disease and infertility. Like other inflammatory and ulcerative sexually transmitted diseases, gonorrhea also increases the risk of acquiring transmitting HIV.

In the July 8, 2011, Morbidity and Mortality Weekly Report, researchers with the U.S. Centers for Disease Control and Prevention (CDC) reported that N gonorrhoeae appears to be developing resistant to cephalosporins such as cefixime and ceftriaxone, the sole remaining effective class of antibiotics. A growing proportion of gonorrhea in the U.S. has an elevated minimum inhibitory concentration, meaning it takes more of the drug to inhibit or kill the bacteria.

Evaluating more than 6000 gonorrhea samples collected since 2000, the investigators found that the proportion showing at least some degree of cephalosporin resistance rose from 0.02% during 2000-2006 to 0.11% in 2009. Drug resistance was seen most often in men who have sex with men, and was concentrated in Hawaii and California.

Indeed, the following week Magnus Unemo of the Swedish Reference Laboratory for Pathogenic Neisseria reported on July 11 at the International Society for Sexually Transmitted Disease Research in Quebec that for the first time a strain of N gonorrhoeae had been detected that show resistance to all available antibiotics, including cephalosporins.

The newly discovered strain, designated H041 -- which the researchers described as a "superbug" -- was found in samples from a woman in Kyoto, Japan. Kyoto, Unemo noted, has historically been a site of emergence of for resistant gonorrhea.

With the usual drugs rendered ineffective, investigators are studying an antibiotic class called carbapenems that have not previously been used to treat gonorrhea.

“This new data outlines what state and local health departments have been seeing on the ground -- that highly untreatable gonorrhea is near,” William Smith, Executive Director of the National Coalition of STD Directors, stated in a press release. “There are currently no new drugs in development for this infection. If this last class of drugs fails we will have no definitive treatment options for gonorrhea. We call on researchers, government, and partners in industry to make the development of new, effective drug treatments for gonorrhea a public health priority."

References

C del Rio, G Hall, EW Hook, et al (CDC).Cephalosporin Susceptibility Among Neisseria gonorrhoeae isolates -- United States, 2000-2010. Morbidity and Mortality Weekly Report 60(26):873-877. July 8, 2011

M Ohnishi, M Unemo, D Golparian, et al. The new superbug Neisseria gonorrhoeae makes gonorrhoea untreatable -- First high-level ceftriaxone resistance worldwide and public health importance. International Society for Sexually Transmitted Disease Research. Quebec, Canada. July 10-13, 2011. Abstract O3-S4.01.

Other Sources

National Coalition of STD Directors. Gonorrhea's Growing Drug Resistance Concerns CDC Officials. Press release. July 11, 2011.