The researchers estimated the prevalence of Helicobacter pylori resistance to antimicrobials in the United States.
They also characterized risk factors associated with H. pylori antimicrobial resistance, and explored the association between drug utilization and antimicrobial resistance patterns over time.
The findings of the study were published in the latest issue of the Annals of Internal Medicine.
A total of 3624 patients (each of whom contributed one isolate) from 20 nationwide trials of H. pylori eradication were included in the study.
The team measured the rates of H. pylori resistance to clarithromycin, metronidazole, and amoxicillin, according to geographic region, age, sex, study year, ethnicity, ulcer status, test method, and study.
Overall resistance to clarithromycin, metronidazole, and amoxicillin was 10.1% (360 of 3571 patients), 36.9% (1063 of 2883 patients), and 1.4% (48 of 3486 patients), respectively.
|Resistance to antimicrobial agents:|
| Annals of Internal Medicine |
In multivariable analyses, multiple risk factors were found to be associated with resistance to individual agents.
Clarithromycin resistance was significantly associated with geographic region, older age, female sex, inactive ulcer disease, and study.
The researchers found that metronidazole resistance was significantly associated with female sex, earlier year of study enrollment, Asian ethnicity, use of an epsilometer test, and study.
Amoxicillin resistance was low and was not significantly associated with any risk factor.
In the 1990s, when rates for use of oral macrolides and metronidazole were relatively stable, clarithromycin resistance rates were stable and metronidazole resistance rates varied.
Author Joette M. Meyer, of the United States Food and Drug Administration, Rockville, Maryland, concluded on behalf of the group, "Clinicians should consider risk factors for antimicrobial resistance when deciding which patients should have susceptibility testing and when choosing appropriate H. pylori treatments in the empirical setting."