A new report indicates that resistant isolates of gonorrhea were detected in more European countries in 2017, and may soon threaten the current recommended treatment protocol.
More countries in the European Union and European Economic Area (EU/EEA) reported antibiotic-resistant isolates of Neisseria gonorrhoeae in 2017, according to a new surveillance report from the European Centre for Disease Prevention and Control (ECDC).
Gonorrhea treatment often includes dual therapy with azithromycin and ceftriaxone. However, resistance among gonococcal isolates to azithromycin recently led health officials in the United Kingdom to cease recommending the dual therapy with azithromycin, replacing it with increased doses of ceftriaxone, the use of ciprofloxacin in certain cases, and adding extra-genital testing in cases of known or suspected antimicrobial resistance. The new ECDC report details surveillance data on antibiotic resistance patterns among gonorrhea isolates collected in Europe and reports that azithromycin resistance threatens the effectiveness of the current regimen.
“The emergence and spread of antimicrobial resistance in Neisseria gonorrhoeae is a serious threat to the treatment and control of gonorrhea,” the investigators wrote in the report. “The main therapeutic agents currently recommended in Europe, extended-spectrum cephalosporins, are the last remaining options for effective empiric first-line antimicrobial monotherapy.”
The 2017 European Gonococcal Antimicrobial Surveillance Programme (Euro-GASP) report included the testing of 3248 isolates, 84.5% of which were collected from male patients. Of the specimens collected, 72.8% were genital, 14.6% were rectal, and 8.5% pharyngeal. Additionally, 15.4% of patients were HIV positive, 96.2% of whom were men who have sex with men. Of the isolates collected in 2017, none showing resistance to ceftriaxone were detected, although resistance levels to cefixime and azithromycin were 1.9% and 7.5%, respectively, staying stable from the prior year’s resistance levels of 2.1% and 7.5%. The proportion of isolates showing ciprofloxacin resistance was 46.5%, the same as in 2016.
“Even though the level of resistance to cefixime is stable, cefixime resistance needs to be monitored closely, particularly because gonococcal strains with resistance to both cefixime and ceftriaxone have been spreading internationally in the last years,” the investigators write. “Novel antimicrobials and/or new dual antimicrobial therapy regimens and continuing surveillance are essential to ensure that gonorrhea remains treatable.”
The investigators also note that although the absence of ceftriaxone resistance and low level of cefixime resistance is encouraging, the study saw an increase in the number of countries reporting isolates resistant to cefixime and azithromycin. There were 15 countries reporting cefixime resistance in 2017, up from 14 in 2016 and 9 in 2015, and 23 reporting azithromycin-resistant isolates, up from 21 in 2016 and 18 in 2015.
“Although overall resistance levels remained stable for all the antimicrobials in 2017, the European response plan to control the threat of multidrug-resistant N gonorrhoeae in Europe, which is currently under revision, should continue to be observed to help identify and report treatment failures and ensure that gonorrhea remains a treatable infection,” the investigators concluded, noting that documented treatment failures and the international spread of ceftriaxone-resistant gonococcal strains. Monotherapy with azithromycin or ciprofloxacin is not currently recommended for gonorrhea unless isolates show susceptibility to the antibiotics.
With 27 of the 31 EU/EEA countries now included in Euro-GASP, the program has set objectives including the strengthening of the surveillance of gonococcal antimicrobial susceptibility, improving isolate numbers and reporting of epidemiological data, and developing increased capacity for gonococcal culture and susceptibility testing across countries.