* Canadian scientists document several cases of treatment
* CDC official says "it's only a matter of time" to reach
By Julie Steenhuysen
CHICAGO, Jan 8 The only remaining oral
antibiotic used for gonorrhea failed to cure the infection in
nearly 7 percent of patients treated at a clinic in Toronto,
Canadian researchers said on Monday in the first published study
of treatment-resistant gonorrhea in North America.
The study raised alarm among U.S. health officials, who have
ordered doctors to stop prescribing the antibiotic known as
cefixime because lab cultures showed gonorrhea was starting to
develop resistance to the drug.
That left U.S. doctors with only one effective treatment for
most cases of gonorrhea, an injectible antibiotic known as
"We've been very concerned about the threat of potentially
untreatable gonorrhea in the United States," Dr. Gail Bolan,
director of the Centers for Disease Control and Prevention's
division for sexually transmitted diseases, said in a telephone
There have been a number of cases in Europe, but "this is
the first time we've had such a report in the actual North
American continent," she said. "We feel it's only a matter of
time until resistance will occur in the United States."
Until now, signs of antibiotic resistance in North America
have been detected mostly through lab tests, which have shown a
steady increase in the amount of antibiotic cefixime - marketed
by Lupin Ltd as Suprax - that was needed to kill gonorrhea.
"We had seen one case beforehand, but this is the first
published report, and it's also the first series of cases in
North America," said Dr. Vanessa Allen of Public Health Ontario
in Canada, who led the study published in the Journal of the
American Medical Association.
Allen and colleagues studied nearly 300 individuals with
gonorrhea between May 2010 and April 2011 who were treated with
cefixime at a clinic in Toronto, looking for any patients who
were still infected during a follow-up visit.
Of the initial 300, 133 returned for retesting. Of those, 13
were still infected, but only nine said they had not had sexual
contact that might have reinfected them. That left a failure
rate of 6.7 percent.
Allen said the study is a preliminary finding, but still
important because it offers some confirmation that people
treated with cefixime are not being cured.
It also points out a weakness of newer DNA-based tests
commonly used to test for gonorrhea.
Previously, doctors would take fluid samples from patients
and grow cultures of gonorrhea bacteria in lab dishes, which
could then be used to identify drug resistance. More advanced
DNA-based tests, such as nucleic acid amplification tests,
cannot be used to test for antibiotic resistance.
"I do think reinvesting in culture-based methodologies is
warranted," Allen said, adding that doctors should consider
sending patients for retesting to make sure they have been
If left untreated, gonorrhea can lead to pelvic inflammatory
disease, ectopic pregnancy, stillbirths, severe eye infections
in babies and infertility in both men and women.
In the United States, there are approximately 300,000
reported cases of gonorrhea each year. But because infected
people often have no symptoms, the actual number of cases is
likely closer to 600,000, Bolan said.
So-called "superbug" drug-resistant strains of gonorrhea
accounted for almost one in 10 cases of sexually transmitted
disease in Europe in 2010, more than double the rate of the year
before, health officials from the Stockholm-based European
Centre for Disease Prevention and Control said in June.
In addition to closely monitoring for resistance, Bolan said
the CDC it is working with its partners at the National
Institutes of Health and pharmaceutical companies to encourage
the development of new antibiotics and test new combinations of