ECDC releases guidance to address XDR gonorrhea threat

Three cases of extensively drug-resistant gonorrhea were identified in the United Kingdom and Australia earlier this year, prompting the European Center for Disease Prevention and Control to issue guidance based on its assessment of the “public health issue.”

All three infections were resistant to most treatment options, including ceftriaxone and azithromycin, which are widely recommended as first-line dual therapy by WHO and other health agencies, according to the European Center for Disease Prevention and Control (ECDC).

One of the infections was reported in the U.K. in February and the other two were reported in Australia in March. The cases were not epidemiologically linked.

The case in the U.K. was a heterosexual man who had female sexual contact in Southeast Asia 1 month before symptom onset. He was initially treated with ceftriaxone and spectinomycin. At a test-of-cure visit, a urine sample tested negative for gonorrhea; however, a pharyngeal swab culture was positive. The infection was ultimately cleared with a 3-day course of IV ertapenem. One of the cases in Australia was also acquired in Southeast Asia, according to the ECDC report. The agency stated that more cases of extensively drug-resistant (XDR) gonorrhea in Southeast Asia are likely being imported to other countries.

“Data on antimicrobial resistance surveillance for Southeast Asia are limited, which in turn makes it difficult to estimate the scope of the problem,” an ECDC spokesperson told Infectious Disease News. “It makes strong European surveillance all the more important because only then can we detect resistant strains early.”

All three XDR gonorrhea isolates appeared to be susceptible to spectinomycin; however, the ECDC warned that this treatment is less effective against pharyngeal gonorrhea. This is highlighted by the treatment failure in the U.K. case, the agency said. The isolates may also be susceptible to gentamicin, although the resistance breakpoint for this drug has not yet been defined by the European Committee on Antimicrobial Susceptibility Testing or the Clinical and Laboratory Standards Institute. In addition, although gentamicin has proven to be effective when given in combination with azithromycin, less is known about its efficacy as monotherapy.

Guidelines for alternative treatment options for gonorrhea are currently being reviewed by the International Union against Sexually Transmitted Infections. However, the ECDC noted that the lack of currently available treatment options for XDR gonorrhea underscore the need for new antimicrobials and an effective vaccine.

“In the long-term, the development of new antimicrobials and an effective vaccine could make a significant impact on the control of antimicrobial resistance and gonorrhea,” the report stated. “Although some progress has been made on the former, with three antimicrobials currently completing phase 2 or phase 3 trials, a vaccine for gonorrhea remains some way away, despite recent developments. Increased advocacy to prioritize and fund research in novel gonorrhea treatment options and vaccine development is required.”

In its Rapid Risk Assessment, the ECDC urged clinicians to “be aware” of the possibility for additional XDR gonorrhea cases and to manage infections based on national and international guidelines. According to a recent MMWR, most patients with gonorrhea in the United States are being treated as the CDC recommends, but nearly one in five patients are not. Most of these patients received monotherapy, which the CDC said may result in treatment failure and accelerate antibiotic resistance.

The ECDC spokesperson also reinforced the need to ensure that all patients with gonorrhea return for a test-of-cure visit so that health care providers can identify any possible treatment failures. According to the agency, it is likely that many patients in Europe fail to do so, increasing the risk for transmission. The ECDC further emphasized the need to submit samples for culture and antimicrobial susceptibility testing.

“In case of XDR gonorrhea, clinicians should consider taking pharyngeal samples irrespective of reported sexual practices,” the report said. “Sexual health services also need to ensure that partner notification is undertaken for all cases.” – by Stephanie Viguers

References:

ECDC. Rapid Risk Assessment: Extensively drug-resistant (XDR) Neisseria gonorrhoeae in the United Kingdom and Australia. https://ecdc.europa.eu/en/publications-data/rapid-risk-assessment-extensively-drug-resistant-xdr-neisseria-gonorrhoeae-united. Accessed May 25, 2018.

Weston EJ, et al. MMWR Morb Mortal Wkly Rep. 2018;doi:10.15585/mmwr.mm6716a4.