ATLANTA – A cluster of gonorrhea cases from the state of Hawaii has been identified as the first in the United States to show decreased susceptibility to ceftriaxone and azithromycin, the two most commonly prescribed drugs used to treat the infection.
“We’re seeing new, troubling signs that our current gonorrhea treatment is losing its effectiveness [but] we’ve not seen a treatment failure in the U.S.,” explained Jonathan Mermin, MD, director of the National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, during a conference on STD prevention sponsored by the Centers for Disease Control and Prevention.
Dr. Jonathan Mermin
Isolates were collected from seven individuals in Hawaii during April and May of this year, all of which showed “dramatically higher levels” of resistance to azithromycin in laboratory testing than has normally been seen in the U.S. While large-scale resistance to azithromycin is something the CDC has watched for several months, four of these seven isolates also demonstrated less vulnerability to ceftriaxone, the first time that has occurred. Since 2010, the recommended treatment for gonorrhea has consisted of a single ceftriaxone shot and an oral dose of azithromycin; having a cluster with increased resistance to both is problematic on several levels, infectious disease experts say.
According to Alan Katz, MD, of the University of Hawaii in Honolulu, “the state of Hawaii has been a seminal site for monitoring Neisseria gonorrhoeae resistance, and the Hawaii state Department of Health has been one of the original CDC gonococcal isolate surveillance program surveillance sites since its inception in 1986.” Hawaii typically sees more gonorrhea cases than the rest of the country, partially due its location between the U.S. and Asia, the latter of which Dr. Katz explained is “where we believe many [drug]-resistant strains originate.”
Currently, trials are underway to identify a new treatment that can replace the current regimen, with promising early results. The drug in question, known as ETX0914, is a single-dose oral therapy that would substitute for ceftriaxone in the currently recommended treatment protocol. Stephanie N. Taylor, MD, of Louisiana State University in New Orleans, shared results of a randomized controlled trial, in which 179 subjects – 167 males and 12 females – received either 2g or 3g doses of only ETX0914, or only ceftriaxone.
A total of 47 subjects received the 3g ETX0914 dose, while 49 subjects received the 2g dose, and the rest received ceftriaxone. All patients (47/47) receiving the 3g dose were cured, and 98% (48/49) in the 2g dose were cured, with only 21 subjects (12%) in the entire study population reporting mild side effects.
“We are very pleased with these results and look forward to seeing ETX0914 advance through additional clinical trials,” Dr. Taylor said in a statement.
For now, health care providers are encouraged to continue with the currently recommended drug therapy, which is still effective. In a statement, Gail Bolan, MD, director of the Division of STD Prevention at the CDC, reminded providers that infections should be treated immediately in order for the drugs to have their full impact.
“All health care providers should also promptly report any suspected treatment failure to local health officials and CDC to ensure rapid response to cases or clusters of concern,” she added.