A recent Toronto-based study has found significant resistance to cefixime, the only oral antimicrobial medication recommended for the treatment of gonorrhea.
Although resistance has been previously documented elsewhere, the study, published in January in the Journal of the American Medical Association, presents the first cases of clinical failure to cefixime in North America, with the same levels of gonorrhea present in patients during the test-of-cure as the initial test.
Conducted between May 1, 2010 and April 30, 2011 at a Toronto sexual health clinic, the study reported a “relatively high” overall rate of clinical failure of 6.77 per cent among the patients who were treated for gonorrhea and returned for a test-of-cure.
With an acceptable efficacy rate of 95 per cent, as set out by the Centre for Disease Control and World Health Organization, the 6.77 per cent failure rate does not meet the standards.
The Public Health Agency of Canada currently recommends cefixime as part of one of two treatment options for gonorrhea. The recommended treatments for gonorrhea, last updated in December 2011, are either a combination of the oral antibiotics cefixime and azithromycin, or a combination of intramuscularly injected cefriaxone and oral azithromycin.
The American CDC, European, and British guidelines no longer recommend cefixime for the treatment of gonorrhea.
Vanessa Allen, medical microbiologist and infectious disease specialist of Public Health Ontario and the principal investigator of the study, says the study’s findings, and observations of antibiotic resistance in Ontario Neisseria gonorrhoeae, are prompting Ontario to release new guidelines.
Allen says the findings are a concern not only because cefixime is considered to be the “backbone” of therapy for gonorrhea, but also because they limit the potential of a program called Expedited Partner Therapy, in which infected patients are also given antibiotics for their sexual partner(s).
Allen says although it is preferable for the partner(s) to see a doctor, the program is effective in cases where they are hesitant. Pills enabled the partner to be treated without coming in to see a doctor. “A shot can’t do that,” says Allen.
Although she describes gonorrhea as a nuisance disease, resistance to all antibiotics in the long-term may mean a return to the days when the disease would infect the blood, joints, and heart.
Allen is currently working on two related studies—one that involves looking at the synergy of using two antibiotics simultaneously to treat gonorrhea in order to slow down resistance, and another that investigates how resistance develops.
At the moment, she says, “the goal is to make sure that each person is treated the best way that they can be.”
Jane Heffernan, associate professor in York’s Department of Mathematics & Statistics and Centre for Disease Modelling, stresses the importance of taking antibiotics exactly as prescribed for the full length indicated in order to ensure effective treatment. She also says that if you are infected with an antibiotic-resistant strain of an illness, it is possible to pass it along to your partner.
For students seeking to reduce their risk of being infected by gonorrhea or any other sexually transmitted disease, Heffernan encourages safe sex practices and open communication with previous and current sexual partners.
“Safe sex practices include taking precautions for all types of sexual activity including anal, vaginal, and oral sex,” says Heffernan. She says STDs can still be transmitted in the absence of ejaculation, and recommends knowing your partner’s sexual history, reporting sexual relations with STD-infected people to a doctor for evaluation, and telling your partner if you’ve contracted an STD so they can get tested and seek treatment.
Vanessa Del Carpio, Staff Writer
