6A 2 Cephalosporin Antimicrobial Susceptibility of Neisseria Gonorrhoeae in the United States, 20092013

Thursday, June 12, 2014: 9:35 AM
Dogwood A
Robert Kirkcaldy, MD, MPH1, John Papp, PhD1, Olusegun Soge, PhD2, Edward W. Hook III, MD3, Carlos del Rio, MD4, Susan Harrington, PhD5, Grace Kubin, PhD6 and Hillard S. Weinstock, MD, MPH7, 1Division of STD Prevention, Centers for Disease Control and Prevention, Atlanta, GA, 2Neisseria Reference Laboratory, Center for AIDS and STD, Departments of Global Health and Medicine, University of Washington, Seattle, WA, 3Division of Infectious Diseases, University of Alabama at Birmingham, Birmingham, AL, 4Rollins School of Public Health, Emory University, Atlanta, GA, 5Cleveland Clinic, Cleveland, OH, 6Laboratory Services Section, Texas Department of State Health Services, Austin, TX, 7Division of STD Prevention/Surveillance and Data Management Branch, Centers for Disease Control and Prevention, Atlanta, GA

Background:  Emerging gonococcal cephalosporin resistance is an urgent public health threat.  Gonococcal cefixime minimum inhibitory concentrations (MICs) increased in the US during 2006-2010; the largest increases were observed in the West and among men who have sex with men (MSM).   In response, CDC updated its treatment recommendations in 2012 and now recommends ceftriaxone-based dual therapy as the only first-line option.  We describe the most recent US gonococcal cephalosporin susceptibility trends.

Methods:  The Gonococcal Isolate Surveillance Project (GISP) conducts surveillance of antimicrobial susceptibility in urethral isolates from men.  MICs are determined by agar dilution and clinical information is abstracted from medical records. We defined elevated cefixime MICs as ≥0.25 µg/ml and elevated ceftriaxone MICs as ≥0.125 µg/ml.

Results:  25,308 isolates were collected during 2009–June 2013. The percentage of isolates with elevated cefixime MICs increased from 0.8% (2009) to 1.4% (2010 and 2011), then decreased to 1.0% (2012) and 0.4% (2013). The percentage of isolates with elevated cefixime MICs: peaked among isolates from MSM at 4.0% (2010) and decreased to 0.8% (2013); peaked among isolates from men who have sex with women (MSW) at 0.5% (2011) and decreased to 0.2% (2013); and peaked in the West in 2010 (3.3%) and then decreased (1.0% in 2013). Similar patterns were observed in other regions, but with smaller initial increases and later peaks. The percentage of isolates with elevated ceftriaxone MICs increased slightly from 0.3% (2009) to 0.4% (2011) and decreased to 0.1% (2013). Recent declines were observed in the West and Midwest and in isolates from MSM.

Conclusions:  Following increases in 2009-2010, the percentage of isolates with elevated cefixime MICs decreased in 2012–2013; slight declines were also observed for ceftriaxone.  Although the trends are encouraging, continued surveillance, appropriate treatment of patients with gonorrhea, and the search for new drugs remain critical.