2014 STD Prevention Conference Studies of Interest on Gonorrhea Drug Resistance

More than 500 abstracts are being presented at the 2014 STD Prevention Conference, addressing a wide range of research relevant to enhancing the quality of STD prevention in the United States and globally.

Two important presentations address the threat of drug-resistant gonorrhea, which has been a growing concern in recent years. The abstracts, which suggest that recent changes to CDC’s treatment guidelines are having a positive impact, are summarized below, followed by brief background on the serious threat of untreatable gonorrhea in the United States.

Studies of Interest

New CDC research being presented at this year’s conference shows that the susceptibility of Neisseria gonorrhoeae to cephalosporin antibiotics increased in the United States between 2011 and 2013, reversing decreases in susceptibility observed in recent years. Additionally, a study from San Francisco finds that most providers in the city are successfully implementing revisions to CDC’s treatment guidelines – made in 2010 and 2012. Together, these studies suggest the updated guidelines may be having their intended impact of slowing the emergence of widespread cephalosporin resistance. Nevertheless, the potential that gonorrhea could become untreatable remains real; improved prevention efforts and new treatment options are urgently needed.

Title: Cephalosporin Antimicrobial Susceptibility of Neisseria Gonorrhoeae in the United States, 2009-2013 (Oral Abstract, Session 6A 2)

Overview: A review of CDC’s Gonococcal Isolate Surveillance Project (GISP) data from January 2009 to June 2013 found that while the susceptibility of N. gonorrhoeae to cephalosporin antibiotics had been declining, susceptibility has increased since 2011, following changes to CDC’s gonorrhea treatment guidelines.

• One way to monitor changes in gonorrhea susceptibility is by monitoring the percentage of isolates with elevated minimum inhibitory concentrations (MICs, or the lowest concentration of an antibiotic required to inhibit visible growth of the bacteria in the laboratory). A higher percentage of isolates with elevated MICs might reduce treatment effectiveness and be a warning sign of impending resistance. Declines in MICs are therefore good news as they indicate increased susceptibility to available drugs.
• According to CDC analyses, the percentage of gonorrhea isolates with elevated cefixime MICs increased from 2009 to 2011 (0.8 percent vs. 1.4 percent), but then decreased to 1.0 percent in 2012 and 0.4 percent in 2013.
• Among men who have sex with men, who in recent years have been at greater risk than heterosexual men for infection with resistant strains, prevalence of elevated cefixime MICs decreased from 4.0 percent in 2010 to 0.8 percent in 2013.
• The percentage of isolates with elevated ceftriaxone MICs also decreased from 0.4 percent in 2011 to 0.1 percent in 2012 after increasing from 0.3 percent in 2009.

The study investigators conclude that while these decreases are encouraging, continued surveillance, appropriate gonorrhea treatment, and the search for new drugs and prevention strategies remain critical.

• Contact: Robert Kirkcaldy, CDC
• Location: Dogwood A
• DATE/TIME: Thursday, June 12, 9:30 a.m. – 10:20 a.m.

Title: Adherence to Gonorrhea Treatment Guidelines in San Francisco (Poster, TP 17)

Overview: Researchers from the San Francisco Department of Public Health examined treatment reports from San Francisco providers, finding that the portion of correctly treated gonorrhea cases increased following each change in CDC treatment guidelines (revised in December 2010 and August 2012). A majority of physicians in the city are now adhering to CDC’s recommendations.

• Data was collected from three time periods before and after the respective treatment recommendations: Jan.-Dec. 2010; Dec. 2010-Aug. 2012; and August 2012-August 2013.
• Researchers determined whether each gonorrhea case was treated according to the CDC recommendations in effect during the relevant time period.
• The proportion of gonorrhea cases receiving recommended treatment increased from 35 percent prior to CDC’s 2010 treatment guidelines update, to 73 percent after the 2010 update, then to 82 percent after the 2012 update.

While these findings are encouraging, ensuring that physicians adhere to CDC’s treatment guidelines remains a top priority – in San Francisco and throughout the country. The authors recommend further research to identify the dissemination methods that were most effective in educating providers so that these methods can be replicated across the country.

• Contact: Susan Philip, San Francisco Department of Public Health
• Location: International Ballroom (M2)
• DATE/TIME: Tuesday, June 10 and Wednesday, June 11; 12:00 PM – 1:30 PM

Background on Gonorrhea Drug Resistance

Gonorrhea has progressively developed resistance to every antibiotic prescribed to treat it. Today, cephalosporins – a class of antibiotics that includes cefixime and ceftriaxone – are the backbone of the only remaining recommended treatment regimen for gonorrhea. In response to laboratory data suggesting cefixime was becoming less effective at stopping the growth of the bacteria (and reports of unsuccessful treatment of gonorrhea with cefixime in other countries), CDC updated its gonorrhea treatment guidelines in 2010 and 2012 to recommend more aggressive therapy (a higher dose of ceftriaxone and the use of two antibiotics) and to remove cefixime from the recommended first-line treatment options. Currently, CDC only recommends a combination of the injectable ceftriaxone plus either azithromycin or doxycycline.

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U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES