Clostridium difficile ‐associated disease and Helicobacter pylori seroprevalence: A case‐control study

Background Helicobacter pylori inhabits the stomach and causes persistent inflammation, with changes in gastric acidity. However, it is unclear whether the presence of H pylori plays a role in Clostridium difficile ‐associated disease (CDAD). The study's aim was to examine relationships of H pylori seroprevalence and serum pepsinogens (PGs), as markers of gastric inflammation, with CDAD. Materials and Methods A case‐control study was conducted among 49 CDAD cases and 54 controls (median age 82 years). Using enzyme‐linked immunosorbent assays, sera were tested for H pylori IgG antibody, and PGI and PGII levels. Helicobacter pylori ‐positive samples were tested for IgG antibody to recombinant cytotoxin‐associated gene A (CagA) virulent protein. Logistic regression models were fitted. Results Cases and controls were comparable in age ( P  = .5) and sex distribution (females 62% vs 57%, P  = .6). Helicobacter pylori IgG seroprevalence was 47%, of whom 23% were CagA seropositives. Among cases compared to controls, 43% vs 28% were H pylori seropositive but lacking CagA IgG antibody: adjusted odd ratio (OR) 3.43 (95% confidence intervals [CI] 1.29‐9.10); 18% vs 4% were positive for CagA phenotype: adjusted OR 9.32 (95% CI 1.61‐53.76). This association was not affected by PG levels. Conclusions Helicobacter pylori infection, especially with CagA virulent phenotype, might predispose to C difficile infection in elderly patients.