Gonorrhea may soon become untreatable with current antibiotics, according to Jonathan Mermin, MD, MPH, director of the National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP) of the Centers for Disease Control and Prevention (CDC).
The first known case cluster in the United States of genetically related isolates with high-level azithromycin resistance and decreased ceftriaxone susceptibility to Neisseria gonorrhoeae
(NG) was detected this spring by Hawaii's laboratory surveillance system for gonococcal susceptibility, according to research
presented on September 22 at the 2016 CDC STD Prevention Conference in Atlanta, Georgia.
“Our last line of defense against gonorrhea is weakening,” Dr. Mermin, who was not a study author, said in a press release
. “If resistance continues to increase and spread, current treatment will ultimately fail and 800,000 Americans a year will be at risk for untreatable gonorrhea.”
"Reduced antimicrobial susceptibility starts in Hawaii and California and moves east. This is probably due to sources in Asia," said lead study author Alan Katz, MD, MPH, professor and associate director of the Office of Public Health sciences at the University of Hawaii, and member of the Hawaii State Board of Health, who presented their findings in a talk on September 22.
In 2011, Hawaii reported the first NG isolate in the United States that had high-level azithromycin resistance. Since 2014, the prevalence of reduced azithromycin susceptibility in the United States has increased, but the strains have been highly susceptible to cephalosporins.
Dr. Katz and his colleagues reported on the first cluster of cases to show decreased susceptibility to both azithromycin and ceftriaxone in isolates they collected from seven patients in Honolulu who had no known epidemiological commonality.
The researchers collected isolates over the course of about three weeks in the Hawaii Department of Health’s (HDOH) STD clinic and two private practice settings, and tested antimicrobial susceptibility by E-test at HDOH’s State Laboratory Division. Azithromycin minimum inhibitory concentrations (MICs) of greater than 256 µg/ml were considered to have high-level resistance; ceftriaxone MICs of 0.125 µg/ml or higher were considered to have reduced susceptibility. The researchers interviewed the patients, and they interviewed, tested, and treated their partners whenever possible.