Clostridioides difficile infection after pneumonia in elderly patients: which antibiotic is at lower risk?

Background: Clostridioides difficile infection (CDI) is a frequent and severe complication of antibiotic treatment in elderly patients hospitalized for acute pneumonia (AP). Aim: To assess the burden and risk factors of CDI and to determine which of the usual antibiotics regimens is at lower risk for post-AP CDI incidence. Methods: Among patients aged >75 years hospitalized for AP in all departments of a university hospital between 2007 and 2017, all the 92 patients developing CDI were compared with 213 patients without CDI. Factors associated with (i) in-hospital and oneyear mortality and (ii) CDI incidence were assessed using logistic regression models. Findings: In patients with and without CDI after AP, mortality rates were respectively at 34% vs 20% in hospital and 63% vs 42% at one year. After adjustment for confounders, CDI was associated with a two-fold risk of in-hospital and one-year mortality after pneumonia (respectively, odds ratio (OR): 1.95; 95% confidence interval (CI): 1.06-3.58; and OR: 2.02; 95% CI: 1.43-7.31). High number of antibiotics (per antibiotic, OR: 1.89; 95% CI: 1.18 -3.06) rather than antibiotics duration (per day, OR: 1.04; 95% CI: 0.96-1.11) was associated with a higher risk of CDI. Compared with other antibiotics, use of penicillin + beta-lactamase inhibitors was associated with a lower risk of CDI (OR: 0.43; 95% CI: 0.19-0.99). Conclusion: In elderly inpatients, CDI greatly increases the burden of AP in the short and long term. If confirmed, these results suggest the preferential use of penicillin thorn beta-lactamase inhibitors for a lower incidence of CDI in elderly inpatients with AP. (C) 2020 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.