Gonorrhea Continues to Show High Levels of Resistance to Azithromycin Across EU

Gonorrhea is the second most common sexually transmitted infection in the European Union/European Economic Area (EU/EEA)—more than 75,000 cases were reported in 2016.

In 2009, the European Center for Disease Prevention and Control (ECDC) launched a program focused on coordinated surveillance of Neisseria gonorrhea antimicrobial susceptibility in the EU/EEA. The surveillance is designed to detect emerging, as well as increasing, antimicrobial resistance and make data readily available to develop appropriate treatment guidelines.

The ECDC has released the results of the 2016 European Gonococcal Antimicrobial Surveillance Program (Euro-GASP) which reports that Neisseria gonorrhea continues to show high levels of resistance to azithromycin across the EU.

The current European guidelines recommended for treatment of gonorrhea include the use of 2 cephalosporin antimicrobials, ceftriaxone or cefixime in combination with azithromycin. Euro-GASP conducts annual surveillance focused on these agents to verify that gonorrhea is being successfully treated.

As part of the surveillance process, EU/EEA countries submit isolates to test susceptibility of gonorrhea to the antibiotics recommended to treat the infection.

In 2016, 25 countries collected and tested 2660 isolates for assessment, which accounted for about 4% of total cases. Patients for which there was available data ranged in age from <1 year to 93 years with a median age of 30 years. A total of 27.5% of patients were under 25 years and 85.1% of isolates were collected from men. According to the report, 59.6% of infections were reported in heterosexual men and women and the remaining 40.4% of infections were linked to men who have sex with men.

Using isolates from specimens collected via genital (75.5%), rectal (14.2%), and pharyngeal (6.4%) sites, the investigative team found that the isolates demonstrated stable rates of resistance against cefixime (2.1%) and azithromycin (7.5%) compared with 2015, when resistance rates were 1.7% and 7.1%, respectively.

In 2016, a total of 14 countries were found to have cefixime-resistant isolates, an increase from the 9 countries reported in 2015. Similarly, 21 countries produced isolates resistant to azithromycin in 2016, which was an increase from the 18 countries reported in 2015. However, no isolates with resistance to ceftriaxone were detected, compared with 1 found in 2015, 5 in 2014, and 7 in 2013.

“While the absence of ceftriaxone resistance among the tested isolates in 2016 is encouraging,” the authors said in a recent statement, “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 patients with available data on their treatment, 86% were administered ceftriaxone and more than half received combined treatment with azithromycin. The use of 2 antimicrobials has likely contributed to increased susceptibility to ceftriaxone, according to investigators.

Successful treatment of gonorrhea reduces complications including pelvic inflammatory disease, ectopic pregnancies, infertility, or increased HIV transmission.

Currently, treatment is one of the main public health strategies to reduce further transmission. Therefore, it is essential to continue surveillance of gonorrhea as well as work toward developing novel antimicrobial and/or dual therapy regimens to prevent gonorrhea from becoming untreatable.

Due to the lack of limited options for combination therapy, the ECDC has launched a response plan in the EU/EEA to control multidrug-resistant gonorrhea and minimize the threat of the infection.