Antibiotic resistance doubles in just 2 decades in Europe

Antibiotic resistance of Helicobacter (H.) pylori has more than doubled in Europe in the past two decades, raising alarm on the gravity of the issue of growing bacterial resistance to commonly-used antibiotics, a study presented at UEG Week 2019 has shown.  

“H. pylori infection is already a complex condition to treat, requiring a combination of medications. With resistance rates to commonly used antibiotics such as clarithromycin increasing at an alarming rate of nearly 1 percent per year, treatment options for H. pylori will become progressively limited and ineffective if novel treatment strategies remain undeveloped,” said lead author Professor Francis Megraud of University of Bordeaux in Bordeaux, France.

“Antibiotic resistance of H. pylori is the main cause of failure of most current eradication regimens,” he said. “The reduced efficacy of current therapies could maintain the high incidence rates of gastric cancer and other conditions such as peptic ulcer disease, if drug resistance continues to increase at this pace.”

The researchers found that resistance to clarithromycin, an antibiotic commonly used to eradicate H. pylori, had risen to 21.6 percent in 2018 compared with 9.9 percent in 1998. [UEG Week 2019, abstract OP035]  

Resistance to two other antibiotics, levofloxacin and metronidazole, was also on the rise — with that for metronidazole increasing from 33.1 percent in 2008 to 42 percent in 2018. 

According to Megraud, resistance to clarithromycin has risen beyond the defined threshold (ie, 15 percent) needed to test for a patient’s resistance to the antibiotic before prescribing it. 

“When it is not possible to test the patient H. pylori strain, it is important to have some knowledge on the global resistance in the country or area especially for clarithromycin and levofloxacin,” he highlighted.

In fact, area-specific data revealed that out of the 18 countries analysed, 15 showed primary resistance to clarithromycin that was above the 15-percent threshold for resistance testing before prescribing. The rate of resistance was highest in Southern Italy (39.9 percent), followed by Croatia (34.6 percent) and Greece (30 percent), which was in keeping with previous estimates by OECD* that both Italy and Greece would have the greatest number of deaths by 2050 amongst European countries due to antimicrobial resistance.

Participants in the study were 1,232 patients who were tested positive for H. pylori from 18 countries across Europe and who had not previously received eradication treatment. Only five out of the 18 countries had clarithromycin resistance below the 15-percent threshold for resistance testing, and they were mainly Northern European countries: Lithuania (13.0 percent), Netherlands (9.2 percent), Norway (8.9 percent), Latvia (6.8 percent), and Denmark (5.0 percent).

“We now want to correlate these data of susceptibility with the data of antibiotic consumption in the different European countries,” said Megraud, who noted that the high resistance rates in the top three countries have previously been attributed to an overuse of antibiotics and lack of institutional support for containment strategies against antibiotic resistance in these countries.

Prudent use of antibiotics as advised by the WHO and limiting unnecessary use of antibiotics can help slow down the development of antibiotic resistance, he urged.  

When asked about alternatives to clarithromycin, Megraud said that quadruple therapies are effective as an alternative to clarithromycin-containing triple therapies, “but lead to adverse events during the treatment and after due to their impact on the gut microbiota and selection of resistance bacteria other than H. pylori.”