Evolution of antibiotic resistance pattern of Helicobacter pylori in Spanish children: A 10-year multicenter study.

Objectives: To delineate the evolution of antibiotic resistance over the past decade in Spanish children diagnosed with Helicobacter pylori (H. pylori) infection.

Methods: An observational, retrospective, multicenter study was conducted in Madrid, Spain. This study included children diagnosed with H. pylori infection via endoscopy with positive culture and antimicrobial susceptibility testing between 2011 and 2020.

Results: A total of 1205 patients (56.7% female) were included in the study. Of these, 18.7% had previously undergone unsuccessful treatment. The resistance to the antibiotics tested was as follows: clarithromycin, 42.9% (n = 504, [95% confidence interval, CI: 40.1%-45.8%]); metronidazole, 24% (n = 280, [95% CI: 21.5%-26.5%]); rifampicin, 14.8% (n = 120, [95% CI: 12.4%-17.4%]); levofloxacin, 5.2% (n = 58, [95% CI: 3.9%-6.6%]); amoxicillin, 2.6% (n = 30, [95% CI: 1.7%-3.6%]); and tetracycline, 0.9% (n = 10, [95% CI: 0.4%-1.6%]). The double resistance rate was 12.2% (n = 143, [95% CI: 10.4%-14.2%]). During the study period, antibiotic resistance remained relatively stable, with a notable decrease in metronidazole (incidence rate ratio [IRR]: 0.941, [95% CI: 0.898-0.985], p = 0.01) and double resistance (IRR: 0.933, [95% CI: 0.875-0.995], p = 0.03) values. The overall eradication rate was 76.6% (n = 752, [95% CI: 73.8-79.2%]), which was significantly higher in patients without prior treatment. The temporal progression of eradication rates showed a substantial increase, with an average annual increase of 2.9% (IRR: 1.029, [95% CI: 1.015-1.043], p < 0.001).

Conclusions: The prevalence of antibiotic resistance in our setting (Madrid, Spain) was remarkably high and remained stable throughout the study period, except for a notable decline in metronidazole and double resistance.