H. pylori treatment not tied to C. difficile infection

Treatment of Helicobacter pylori (H. pylori) infection is not linked to an increased risk of Clostridium difficile (C. difficile) infection, according to a retrospective cohort study.

The researchers used data from the Veteran’s Health Administration (VHA) to identify 38,535 individuals (median age 61.8 years, 91.8 percent male) diagnosed with H. pylori infection between 1994 and 2018. Of these, 74.8 percent (n=28,818) received H. pylori eradication therapy. The most common treatment regimens were amoxicillin- and clarithromycin-based triple therapy (51.6 percent), while 8.3 percent received bismuth-based quadruple therapy.

C. difficile infection developed in 284 patients (0.74 percent) within 3 months of H. pylori infection. [Am J Gastroenterol 2020;115:716-722]

Overall, individuals with a recent hospital admission had a higher risk of C. difficile infection, be it those hospitalized 4 weeks (OR, 3.46, 95 percent CI, 2.18–5.48) or 12 weeks prior (OR, 2.15, 95 percent CI, 1.22–3.77; p<0.001 for both). Previous C. difficile infection was also associated with a higher risk of C. difficile infection (OR, 12.5, 95 percent CI, 9.21–17.0; p<0.001). Women appeared to be at greater risk of C. difficile infection (OR, 1.74, 95 percent CI, 1.20–2.52; p=0.003).

There was no association between H. pylori treatment and C. difficile infection, and no link between choice of H. pylori eradication regimen or antibiotic class with risk of C. difficile infection. Proton pump inhibitor (PPI) use, be it long-term use or as a component of H. pylori eradication therapy, also did not affect risk of C. difficile infection.

However, due to the lack of information on PPI duration of use and its ease of availability, the non-association between PPI therapy and C. difficile infection cannot be established, said the researchers.

Of the 28,818 patients who received eradication therapy, 26.2 percent had a confirmation of eradication, while 3.2 percent tested positive for H. pylori infection upon retesting.

Confirmed eradication was not tied to an increased risk for C. difficile infection (OR, 1.49, 95 percent CI, 0.67–3.29). The researchers acknowledged that this finding could either be statistical (eg, sample size, insufficiently powered) or reflect a true lack of association.

“[Previous research has suggested] that eradication of H. pylori can be associated with antibiotic resistance, antibiotic-associated diseases, and changes in the microbiome that could have downstream consequences,” the researchers said. Of note is the potential link between treatment of H. pylori infection with subsequent C. difficile infection, they added.

“Our study … suggests that H. pylori treatment does not increase the risk of C. difficile infection on its own and reaffirms what is known: that history of C. difficile infection and recent hospitalization are the most important factors for future C. difficile infection,” they noted.

In line with the findings from the present study, prior hospital admission or C. difficile infection should be considered before administration of H. pylori eradication therapy.

The researchers acknowledged that the study may not have accounted for all C. difficile infections, such as if the patients were diagnosed with C. difficile infection or received H. pylori eradication therapy outside the VHA setting.

“[O]ur findings suggest that H. pylori should be continued to be treated when detected, given that it likely modifies future gastrointestinal disease risks, including peptic ulcer disease, gastric lymphoma, and adenocarcinoma,” they concluded, calling for further research to establish this finding as well as other risk factors that may predispose certain patients to C. difficile infection.