872. Differences in Neisseria gonorrhoeae Antibiotic Susceptibility among Men by Sex of Sex Partner, United States, 20052010
Session: Oral Abstract Session: Antimicrobial Resistance and Susceptibility
Saturday, October 22, 2011: 10:45 AM
Room: 151AB
Background: Among men with Neisseria gonorrhoeae (NG) infections, men who report having sex with men (MSM) have been disproportionately infected with fluoroquinolone-resistant N. gonorrhoeae.  We examined differences in susceptibility to cephalosporins and other antibiotics used to treat gonorrhea between isolates from MSM and men who reported exclusively having sex with women (MSW).

Methods: The Gonococcal Isolate Surveillance Project (GISP) is a sentinel surveillance system that monitors antibiotic susceptibility of NG isolates collected from men from 27–29 sites.  Minimum inhibitory concentrations (MICs) are determined by agar dilution.  Using data from 2005–2010, we compared the proportion of isolates from MSM and MSW with elevated MICs to cefixime (MIC ≥0.25 µg/ml), ceftriaxone (≥0.125 µg/ml), azithromycin (≥2.0 µg/ml), and tetracycline (≥2.0 µg/ml [resistance]), and tested for trends.  Cefixime susceptibility was not tested during 2007–2008.

Results: During 2005–2010, 35,386 NG isolates were tested for susceptibility; 23% were from MSM.  The percent of isolates exhibiting elevated MICs was higher for MSM compared to MSW for: cefixime (MSM: 1.7%, MSW: 0.2%, p<0.001); ceftriaxone (MSM: 0.4%, MSW: 0.1%, p<0.001); azithromycin (MSM: 0.9%, MSW: 0.2%, p<0.001); and tetracycline (MSM: 37%, MSW: 13%, p<0.001).   Among isolates from MSM, the percent with elevated MICs increased from 2005 to 2010 for cefixime (0.2% in 2005, 3.9% in 2010, p<0.001) and ceftriaxone (0.2% in 2005, 0.9% in 2010, p<0.001); there were no increases among MSW.  There were no changes over time in azithromycin susceptibility among isolates from MSM or MSW.  Tetracycline resistance was high among MSM, increasing from 35% in 2005 to 48% in 2006, and declining to 34% in 2010 (p<0.001); tetracycline resistance increased slightly among MSW (12% in 2005, 14% in 2010, p=0.04).  Of isolates from MSM with elevated cefixime MICs (n=98), 73% were tetracycline resistant and 1% had elevated azithromycin MICs.

Conclusion: MICs to the examined antibiotics were higher among isolates from MSM than MSW, and MICs to cephalosporins increased among isolates from MSM.  Causes of these concerning trends should be elucidated, and gonorrhea treatment and prevention approaches for MSM warrant review.

Subject Category: A. Antimicrobial agents and Resistance

Robert D. Kirkcaldy, MD, MPH1, Carlos del Rio, MD2, Geraldine Hall, PhD3, King Holmes, MD, PhD, FIDSA4, Edward Hook, MD5, Olusegun Soge, PhD6, John Papp, PhD1 and Hillard Weinstock, MD, MPH1, (1)Centers for Disease Control and Prevention, Atlanta, GA, (2)Infectious Diseases, Emory Univ. Sch. of Med., Atlanta, GA, (3)Cleveland Clinic, Cleveland, OH, (4)Center for AIDS & STDs, Seattle, WA, (5)University of Alabama at Birmingham, Brimingham, AL, (6)University of Washington, Seattle, WA


R. D. Kirkcaldy, None

C. del Rio, IDSA: Board Member, Lots of work, no pay
CDC: Grant Investigator, Research grant and Research support
NIH: Grant Investigator, Research grant and Research support

G. Hall, None

K. Holmes, None

E. Hook, None

O. Soge, None

J. Papp, None

H. Weinstock, None

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