Cara N. Wilder, Ph.D.Helicobacter pylori is a Gram-negative, microaerophilic bacterium known to inhabit the stomach lining of at least 50% of the human population. This pathogen is transmitted to humans through the consumption of contaminated food and water, as well as through direct contact with infected individuals. Once ingested, H. pylori will colonize the surface of stomach epithelial cells, resulting in either asymptomatic carriage or complications including chronic gastritis, peptic ulcers, or stomach cancer.
The most common treatment of H. pylori infections is through the use of a triple regimen that combines two antibiotics (clarithromycin, amoxicillin) and a proton pump inhibitor (PPI). Though this treatment is effective in most patients, recent reports have indicated that successful bacterial eradication is decreasing due to the emergence of clarithromycin-resistant strains. To aid in the treatment of these antibiotic-resistant infections, many clinicians have turned toward the use of second-line treatments such as a bismuth-containing quadruple therapy (EBMT) or a moxifloxacin-containing triple therapy (MEA). However, little is known regarding the efficacy of these second-line therapies.
In a recent study, Kim et al. sought to evaluate the rate of H. pylori reinfection following EBMT or MEA treatment. In this analysis, 648 patients who failed bacterial eradication through the standard triple therapy were treated with either the EBMT or the MEA second-line therapies. At four weeks following treatment, patients were examined for H. pylori colonization through either the 13C urea breath test or by invasive analysis. From this investigation, the annual reinfection rate from EBMT and MEA treatment was found to be 4.45% and 6.46%, respectively. Overall, the long-term reinfection rate of H. pylori remained low following both second-line treatments, suggesting that there is no significant evidence that reinfection of H. pylori is related to the eradication program.
