Incidence, risk factors, and health service burden of sequelae of campylobacter and non-typhoidal salmonella infections in England, 2000–2015: A retrospective cohort study using linked electronic health records

Background:Reactive arthritis, irritable bowel syndrome (IBS), Guillain-Barré syndrome, ulcerative colitis, and Crohn's disease may be sequelae ofCampylobacteror non-typhoidalSalmonella(NTS) infections. Proton pump inhibitors (PPI) and antibiotics may increase the risk of gastrointestinal infections (GII); however, their impact on sequelae onset is unclear. We investigated the incidence of sequelae, their association with antibiotics and PPI prescription, and assessed the economic impact on the NHS. Methods:Data from the Clinical Practice Research Datalink for patients consulting their GP forCampylobacteror NTS infection, during 2000-2015, were linked to hospital, mortality, and Index of Multiple Deprivation data. We estimated the incidence of sequelae and deaths in the 12 months following GII. We conducted logistic regression modelling for the adjusted association with prescriptions. We compared differences in resource use and costs pre- and post-infection amongst patients with and without sequelae. Findings:Of 20,471 patients with GII (Campylobacter17,838), less than 2% (347) developed sequelae, with IBS (268) most common. AmongCampylobacterpatients, those with prescriptions for PPI within 12 months before and cephalosporins within 7-days before/after infection had elevated risk of IBS (adjusted odds ratio [aOR] 2.1, 1.5-2.9) and (aOR 3.6, 1.1-11.7) respectively.Campylobactersequelae lead to ∼ £1.3 million, (£750,000, £1.7 million) in additional annual NHS expenditure. Interpretation:Sequelae ofCampylobacterand NTS infections are rare but associated with increased NHS costs. Prior prescription of PPI may be a modifiable risk factor. Incidence of sequelae, healthcare resource use and costs are essential parameters for future burden of disease studies.