Gonorrhea Drug Combo Still Works but for How Long?
According to the Center for Disease Control and Prevention's Morbidity and Mortality Weekly Report, resistance to azithromycin, one of the antibiotics used to treat gonorrhea is emerging.
The CDC currently recommends treating gonorrhea with combination ceftriaxone + azithromycin, and so the increases in reduced susceptibility are a "cause for concern that resistance to these antimicrobial agents might be emerging." Gail Bolan, MD, director of CDC"s Division of STD Prevention added,"It is unclear how long the combination therapy of azithromycin and ceftriaxone will be effective if the increases in resistance persist."
In the United States, gonorrhea is the second most commonly reported notifiable disease where over 350,000 cases were reported in 2014. Prevention primarily relies on prompt detection and effective antimicrobial therapy. However, the absence of routine antimicrobial susceptibility testing during care and the growing antimicrobial resistance to the drugs have affected overall treatment.
The Gonococcal Isolate Surveillance Project (GISP) was established to track trends in antimicrobial susceptibility of N. gonorrhoeae strains in the U.S. Isolates are collected monthly from up to the first 25 men with gonococcal urethritis attending each of the participating STD clinics.
In 2014, a total of 5,093 isolates were collected, of which 25.3% were resistant to tetracycline, 19.2% to ciprofloxacin, and 16.2% to penicillin. There was also an increase from 0.6% to 2.5% from 2013 to 2014 in reduced azithromycin susceptibility (Azi-RS); none of these isolates showed reduced cefixime (Cfx-RS) or ceftriaxone susceptibility (Cro-RS). Cfx-RS increased from 0.1% in 2006 to 1.4% in 2010 and 2011, then decreased to 0.4% in 2013, then increased to 0.8% in 2014. Similarly, Cro-RS increased from 0.1% in 2008 to 0.4% in 2011, then decreased to 0.1% in 2013 and 2014.
The data also showed higher percentage of isolates resistant to tetracycline, ciprofloxacin, penicillin, or all three, among men who have sex with men (MSM) vs. men who have sex with women (MSW). Moreover, susceptibility patterns differed by geographic region within the U.S. and by sex of sex partner.
Prevention, rapid detection, and control of outbreaks of ceftriaxone-resistant N. gonorrhoeae infection should be a U.S. public health priority, according to The National Strategy for Combating Antibiotic-Resistant Bacteria. Other action steps include the development of treatment recommendations for effective prevention and treatment of complications and gonorrhea transmission. In addition, development of national treatment recommendations, prioritizing research and prevention, allocating STD prevention services and resources, and communicating best treatment practices to healthcare providers can be done using GISP data.
“The confluence of emerging drug resistance and very limited alternative options for treatment creates a perfect storm for future gonorrhea treatment failure in the U.S.,” said Jonathan Mermin, M.D., director of the CDC's National Center for HIV/AIDS, Viral Hepatitis, STD, and Tuberculosis Prevention. “History shows us that bacteria will find a way to outlast the antibiotics we're using to treat it. We are running just one step ahead in order to preserve the remaining treatment option for as long as possible.”
For more information visit CDC.gov.