The helicobacter pylori (H. pylori) bacteria, a common bug that can cause stomach infections, developed a high resistance to key antibiotics in the two years since the pandemic started, a small new study has found. The overuse of antibiotics to treat COVID-19 is a likely cause, the researchers say.
H. pylori infection can develop into ulcers and gastritis, and is a controllable risk factor for gastric cancer. The elderly are at high risk of infection from the bug and are most likely to develop antibiotic resistance to it, earlier studies have found.
In the current study, investigators followed outcomes in 233 patients who had been treated for COVID-19 at least three months prior. They were later treated for H. pylori infections with either first-line clarithromycin, esomeprazole and amoxicillin, or an alternate regimen of levofloxacin, esomeprazole and amoxicillin.
In patients who followed through with treatment, clarithromycin was able to eradicate the infection in 65% of cases, and levofloxacin in 74% of cases, investigators found.
Neither regimen had an acceptable eradication rate, according to a report by CIDRAP – Center for Infectious Disease Research & Policy of the University of Minnesota. In addition, the difference in outcomes between the two treatments was not significant.
The findings may be due to the overuse of azithromycin to treat COVID-19, the researchers theorized. Azithromycin has cross-resistance with clarithromycin, CIDRAP noted. Use of this drug and levofloxacin to treat COVID-19 patients may have led to H. pylori mutations, in turn causing greater resistance to treatment.
The rising resistance “can adversely impact the costs of H. pylori treatment and increase the risk of H. pylori related diseases,” the authors of the current study wrote.
Antibiotics and COVID in the U.S.
Although the study was conducted in Egypt, antibiotics overuse has been found in the United States during the early pandemic as well. The drugs — chiefly azithromycin — were commonly prescribed to Medicare beneficiaries diagnosed with COVID-19 during the pandemic’s first year, according to a Centers of Disease Control and Prevention report published in April 2022.
Fully 30% of outpatient visits from April 2020 to April 2021 were linked to an antibiotic prescription and more than half of these were for azithromycin, CDC researchers found.
The current study on H. pylori was published in BMC Infectious Diseases.