Drug Resistance of Gonorrhea in the EU: Persistent but Stable

Neisseria gonorrhoea continues to show high levels of resistance to azithromycin across the European Union and European Economic Area, according to the 2016 results of the European Gonococcal Antimicrobial Surveillance Program (Euro-GASP). This threatens the effectiveness of the currently recommended dual therapy regimen for gonorrhea. Overall, the rates of resistance to cefixime, ceftriaxone and azithromycin have remained stable when compared to recent years.

The main antibiotics currently recommended for gonorrhea treatment in Europe, so-called third generation cephalosporins, are the last remaining options for effective first-line antimicrobial single therapy. As susceptibility of Neisseria gonorrhoea to these antimicrobials had decreased in the past, the European treatment guidelines suggest the addition of azithromycin to the basic course of the cephalosporins ceftriaxone or cefixime.

In order to monitor the continued effectiveness of this treatment regimen, countries of the European Union and European Economic Area (EU/EEA) participate in Euro-GASP sentinel surveillance programme. Each year they submit isolates to test susceptibility of Neisseria gonorrhoeae to the antibiotics commonly used to treat gonorroea.

In 2016, 25 EU/EEA countries collected and tested 2 660 gonococcal isolates showing stable rates of resistance against cefixime (2.1%), ciprofloxacin and azithromycin (7.5%) compared with 2015. No isolates with resistance to ceftriaxone were detected compared with one in 2015, five in 2014 and seven in 2013.

While the absence of ceftriaxone resistance among the tested isolates in 2016 is encouraging, the persistent level of resistance to azithromycin is of concern as it threatens to reduce the effectiveness of the recommended dual therapy with ceftriaxone and azithromycin.

Among those patients for whom information on their treatment course was reported in 2016, 86% were administered ceftriaxone and more than half received combined treatment with azithromycin. The use of two antimicrobials for gonorrhoea treatment has likely contributed to increased susceptibility to ceftriaxone. However, Euro-GASP data completeness for the variable 'treatment used' has still some way to go overall with just 37% in 2016.

With more than 75 000 reported cases in 2016, gonorrhoea is the second most commonly notified sexually transmitted infection (STI) in the EU/EEA countries. Apart from these reports, many more asymptomatic infections are know to occur.

Successful gonorrhea treatment with antibiotics not only reduces the risk of complications such as pelvic inflammatory disease, ectopic pregnancies, infertility or increased HIV transmission in some settings. Combined with regular testing to diagnose and treat infections at an early stage, it also serves as one of the main public health strategies in order to reduce further transmission.

In light of limited alternatives to the current combination therapy introduced in 2012, ECDC launched a regional response plan to control multidrug-resistant gonorrhea to minimize the threat of drug-resistant gonorrhea in Europe. ECDC is currently revising the plan, also following recent reports of extensively drug resistant gonorrhea strains that reached Europe.

Understanding drug-resistant gonorroea: an ECDC whole genome sequencing study http://bit.ly/NgWGS

ECDC: first detected cases of extensively drug-resistant gonorrhoea threaten future treatment https://ecdc.europa.eu/en/news-events/ecdc-first-detected-cases-extensively-drug-resistant-gonorrhoea-threaten-future

ECDC Annual Epidemiological Report for 2016 - Gonorrhea http://bit.ly/AERNG16

ECDC Surveillance Atlas: chlamydia, gonorrhea, syphilis, congenital syphilis and lymphogranuloma venereum http://bit.ly/STI_Atlas

Source: ECDC