Sex Bug Becoming Resistant to Last Known Treatment, WHO Warns
By Daniel J. DeNoon
WebMD Health News
Reviewed by Laura J. Martin, MD
June 6, 2012 -- Gonorrhea is fast becoming untreatable, spurring an urgent call to action by the World Health Organization (WHO).
The WHO alert follows an even more strident warning by CDC researcher Gail A. Bolan, MD, and colleagues.
"It is time to sound the alarm," Bolan and colleagues wrote last February in the New England Journal of Medicine. Resistance to all known antibiotics, they warn, is "threatening our ability to cure gonorrhea."
Gonorrhea bacteria, Neisseria gonorrhoeae, have a long history of evading treatment:
- In the 1940s, gonorrhea became resistant to sulfanilamide.
- In the 1980s, gonorrhea became resistant to penicillin, tetracycline, chloramphenicol, erythromycin, and streptomycin.
- By 2007, gonorrhea became resistant to fluoroquinolones, including ciprofloxacin.
When the dust cleared, there was only one line of defense against gonorrhea: third-generation cephalosporin antibiotics. The currently recommended cephalosporins are injectable ceftriaxone (preferred) and oral cefixime.
Now wily gonorrhea bugs are becoming resistant to these drugs, too. Cefixime resistance increased 17-fold from 2006 to the first six months of 2011. Ceftriaxone resistance increased 10-fold.
Overall, less than 2% of gonorrhea are resistant to cefixime and only 0.5% are resistant to ceftriaxone. So why all the worry?
In the western U.S. -- and among men who have sex with men -- gonorrhea is becoming cephalosporin resistant much faster. It's the same pattern seen when the bug became resistant to fluoroquinolones.
As far as the CDC knows, there haven't yet been any treatment failures -- persistent gonorrhea despite treatment -- in the U.S. But then, only 2% of known U.S. gonorrhea cases are included in the CDC's gonorrhea surveillance program.
And treatment failures already have been seen in Japan, Norway, and the U.K. It's only a matter of time before the bug builds enough resistance to shrug off all existing treatments.
"The trends in decreased [cephalosporin] susceptibility that we're seeing, coupled with the history of emerging resistance and reported treatment failures in other countries, point to the likelihood of [U.S.] treatment failures on the horizon and the need for urgent action to prevent untreatable gonorrhea," CDC spokeswoman Nikki Mayes tells WebMD via email.
Ironically, one problem with tracking treatment-resistant gonorrhea is technology. State and local health labs used to have to culture gonorrhea bacteria in order to identify them. Now they use faster DNA tests.
But the new DNA tests can't yet tell whether gonorrhea is treatment resistant. That can only be done with old-fashioned cultures. And many labs no longer have the needed equipment or expertise for drug-susceptibility testing. Just as we're facing an onslaught of resistant gonorrhea, we're losing our ability to see it coming.
Gonorrhea Resistance Action Plan
The WHO today released its "global action plan" for controlling the spread of drug-resistant gonorrhea. The plan, to which the CDC contributed, calls for:
- Correct use of antibiotics, particularly in "key populations, including men who have sex with men and sex workers."
- Preventing gonorrhea infections, diagnosing them quickly, and treating them appropriately.
- Keeping close track of treatment failures.
- Effective drug regulations and prescription policies for antibiotics.
- Strengthening surveillance for drug-resistant gonorrhea.
- Building regional networks of laboratories that can culture gonorrhea and measure drug resistance.
- Research into new ways to detect and monitor drug-resistant gonorrhea.
- Research into new treatments for gonorrhea.
That last part of the plan -- finding new treatments -- is not far along. The U.S. NIH has only one clinical trial under way. And that trial isn't looking at a new drug. It's only trying to find new combinations of existing drugs that might buy more time against the day gonorrhea becomes untreatable.
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