Proton pump inhibitors and risk of bloodstream infection without an identifiable source: a hospital-based case-control study

The association between proton-pump inhibitor (PPI) use and systemic infections caused by bacterial translocation is unclear. This study aims to investigate whether patients receiving PPI therapy have a higher risk for bloodstream infections (BSI) without an identifiable source of infection, as an alternative indicator of BSI secondary to bacterial translocation. We conducted a hospital-based case–control study which enrolled all patients aged 20 years and older who developed BSI confirmed by two sets of positive blood culture and had inpatient care in Ichinomiya-Nishi Hospital in 2019. Patients’ data were collected from medical records, and bacterial translocation type (BT-type) BSI group were defined as those who had BSI without an identifiable source of infection, whereas the others were classified control group based on the diagnostic criteria for each infectious disease. We analyzed data from 309 patients, including 66 cases and 243 controls. PPI users had a 2.4-fold higher risk of developing BT-type BSI compared to non-PPI-users after controlling for potential confounders (OR: 2.41, 95% CI: 1.29–4.51, p=0.006). In conclusion, PPI use is associated with higher risk of BSI without an identifiable source and therefore, PPI use may increase the risk of septic morbidity secondary to bacterial translocation.