Background & aims: In  2017, the World Health Organization (WHO) designated  clarithromycin-resistant Helicobacter pylori a high priority for  antibiotic research and development. However, there are no clear data on  the global distribution of resistance or its clinical effects. We  performed a systematic review and meta-analysis to assess the  distribution of H pylori resistance to commonly used antibiotics and to  measure the association between antibiotic resistance and treatment  failure.

Methods: We searched publication  databases for studies that assessed rates of H pylori resistance to  clarithromycin, metronidazole, levofloxacin, amoxicillin, or  tetracycline. Pooled estimates of primary and secondary resistance and  95% confidence intervals (CIs) were grouped by WHO region. The  association between antibiotic resistance and treatment failure was  measured by extracting data on treatment efficacy in patients with  resistant and susceptible isolates and pooling odds ratios with 95% CIs.

Results: We  identified 178 studies, comprising 66,142 isolates from 65 countries.  Primary and secondary resistance rates to clarithromycin, metronidazole,  and levofloxacin were ≥15% in all WHO regions, except primary  clarithromycin resistance in the Americas (10%; 95% CI, 4%-16%) and  South-East Asia region (10%; 95% CI, 5%-16%) and primary levofloxacin  resistance in the European region (11%; 95% CI, 9%-13%). There was  considerable heterogeneity (I2 > 75%) among all analyses-this might  have resulted from the grouping of resistance rates by country.  Increasing antibiotic resistance was observed in most WHO regions.  Resistance to clarithromycin was significantly associated with failure  of clarithromycin-containing regimens (odds ratio, 6.97; 95% CI,  5.23-9.28; P < .001).

Conclusions: Resistance  of H pylori to antibiotics has reached alarming levels worldwide, which  has a great effect on efficacy of treatment. Local surveillance networks  are required to select appropriate eradication regimens for each  region.

Keywords: Bacterial Infection; Drug; Epidemiology; Prevalence.