In the Journals

Gonorrhea susceptibility to cephalosporins increases in US

The prevalence of cephalosporin-resistant Neisseria gonorrhoeae appears to have decreased from 2011 to 2014, according to recently published CDC surveillance data.

“The prevalence of reduced cefixime susceptibility declined nearly 70% between 2011 and 2013, suggesting a halting of drift toward resistance,” Robert Kirkcaldy, MD, MPH, of the CDC’s Division of STD Prevention, and colleagues wrote. “Although this improvement in susceptibility appears temporally correlated with treatment guideline changes, we cannot establish a causal relationship.”

Robert Kirkcaldy

Robert Kirkcaldy

The CDC updated its recommendation for gonorrhea treatment in 2010 from single-dose cephalosporin to intensified combination therapy with ceftriaxone or cefixime plus a second antimicrobial, and again in 2012 to recommend ceftriaxone-based combination therapy. To identify trends in susceptibility during these changes, researchers analyzed 2006-2014 data collected by the CDC’s Gonococcal Isolate Surveillance Project. Isolates collected by the sentinel system were obtained from the urethra of men with gonorrhea treated at U.S. public clinics for STDs, and categorized as having reduced susceptibility if displaying either ceftriaxone minimum inhibitory concentrations of 0.125 μg/mL or cefixime minimum inhibitory concentrations of 0.25 μg/mL. Trends in susceptibility identified by the analysis were stratified by region and reported sex of the patient’s partners.

There were 51,144 isolates collected from 34 cities, mostly in the West (36.6%) and South (32.2%). More than 28% of the isolates were drawn from men who have sex with men.

The portion of gonorrhea patients treated with 250 mg ceftriaxone injected intramuscularly increased from 8.7% to 96.6% (P < .001) during the study period. Reduced cefixime susceptibility was detected in 0.1% of isolates in 2006 and increased to 1.4% in 2011. Reduced susceptibility declined to 0.4% in 2013, but then rose again to 0.8% in 2014. Throughout the entire study, isolates obtained from MSM more often demonstrated reduced susceptibility than those collected from men reporting sex with women exclusively.

Although these resistance trends appeared to follow CDC guideline changes, the researchers said it would be premature to claim a direct relationship. In addition, the increase seen in 2014 may imply that improvements in halting drift toward resistance are short-lived.

“The increased prevalence of reduced cefixime susceptibility in 2014 highlights the need to maintain surveillance, search for new therapeutics and ensure that gonorrhea is treated according to the CDC’s guidelines,” they concluded. – by Dave Muoio

Disclosure: Kirkcaldy reports no relevant financial disclosures. Please see the full study for a list of all other authors’ relevant financial disclosures.

*Editor's Note: On Dec. 28, we corrected the first paragraph to clarify that the prevalence of cephalosporin-resistant Neisseria gonorrhoeae appears to have decreased from 2011 to 2014. The editors regret the error.

The prevalence of cephalosporin-resistant Neisseria gonorrhoeae appears to have decreased from 2011 to 2014, according to recently published CDC surveillance data.

“The prevalence of reduced cefixime susceptibility declined nearly 70% between 2011 and 2013, suggesting a halting of drift toward resistance,” Robert Kirkcaldy, MD, MPH, of the CDC’s Division of STD Prevention, and colleagues wrote. “Although this improvement in susceptibility appears temporally correlated with treatment guideline changes, we cannot establish a causal relationship.”

Robert Kirkcaldy

Robert Kirkcaldy

The CDC updated its recommendation for gonorrhea treatment in 2010 from single-dose cephalosporin to intensified combination therapy with ceftriaxone or cefixime plus a second antimicrobial, and again in 2012 to recommend ceftriaxone-based combination therapy. To identify trends in susceptibility during these changes, researchers analyzed 2006-2014 data collected by the CDC’s Gonococcal Isolate Surveillance Project. Isolates collected by the sentinel system were obtained from the urethra of men with gonorrhea treated at U.S. public clinics for STDs, and categorized as having reduced susceptibility if displaying either ceftriaxone minimum inhibitory concentrations of 0.125 μg/mL or cefixime minimum inhibitory concentrations of 0.25 μg/mL. Trends in susceptibility identified by the analysis were stratified by region and reported sex of the patient’s partners.

There were 51,144 isolates collected from 34 cities, mostly in the West (36.6%) and South (32.2%). More than 28% of the isolates were drawn from men who have sex with men.

The portion of gonorrhea patients treated with 250 mg ceftriaxone injected intramuscularly increased from 8.7% to 96.6% (P < .001) during the study period. Reduced cefixime susceptibility was detected in 0.1% of isolates in 2006 and increased to 1.4% in 2011. Reduced susceptibility declined to 0.4% in 2013, but then rose again to 0.8% in 2014. Throughout the entire study, isolates obtained from MSM more often demonstrated reduced susceptibility than those collected from men reporting sex with women exclusively.

Although these resistance trends appeared to follow CDC guideline changes, the researchers said it would be premature to claim a direct relationship. In addition, the increase seen in 2014 may imply that improvements in halting drift toward resistance are short-lived.

“The increased prevalence of reduced cefixime susceptibility in 2014 highlights the need to maintain surveillance, search for new therapeutics and ensure that gonorrhea is treated according to the CDC’s guidelines,” they concluded. – by Dave Muoio

Disclosure: Kirkcaldy reports no relevant financial disclosures. Please see the full study for a list of all other authors’ relevant financial disclosures.

*Editor's Note: On Dec. 28, we corrected the first paragraph to clarify that the prevalence of cephalosporin-resistant Neisseria gonorrhoeae appears to have decreased from 2011 to 2014. The editors regret the error.