Regional Differences In Clostridium Difficile Infections In Relation To Fluoroquinolone And Proton Pump Inhibitor Use, Finland, 2008-2011

Background: Several antimicrobial agents and proton pump inhibitors (PPIs) have been identified as risk factors for Clostridium difficile infections (CDIs). Nationwide laboratory-based surveillance of CDIs in Finland since 2008 has shown variation in regional CDI rates. We evaluated whether regional differences in CDI rates were associated with antibacterial and PPI use. Methods: Data on mean annual incidence rates of CDIs during 2008-2011 in 21 healthcare districts (HDs) were obtained from the National Infectious Disease Register, consumption (median annual use) of antimicrobials and PPIs from the Finnish Medical Agency, availability of molecular diagnostics by a laboratory survey and data on ribotypes from the national reference laboratory. The association over the 4 years was measured by incidence rate ratio (IRR) and we performed both bivariate and multivariate analyses. Results: During 2008-2011, PPI use increased 27% but fluoroquinolone use was stable. The level of fl uoroquinolone use was strongly associated with the mean annual CDI incidence rate in different HDs over the 4-year period, but PPI use had less effect. The molecular diagnostics methodology and PCR ribotype 027 were not independently associated with CDI rate. The final multivariable model only included fl uoroquinolone and PPI use; IRR for fl uoroquinolones was 2.20 (95% confidence interval (CI), 1.32-3.67; p = 0.003). Conclusions: Fluoroquinolone use may play a role in regional differences in CDI rates. Although the use has not recently increased, regionally targeted antimicrobial stewardship campaigns promoting appropriate use of fl uoroquinolones should still be encouraged since they may decrease the incidence of CDIs.