Clostridioides difficile infection after pneumonia in older patients: Which antibiotic is at lower risk?

Clostridioides difficile infection (CDI) is a frequent and severe complication of antibiotic treatment in older patients hospitalized for acute pneumonia (AP).

We aimed 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.

Among patients aged >75y hospitalized for AP in all departments of a university hospital between 2007 and 2017, all the 92 patients developing a CDI were compared with 213 patients without CDI. Factors associated with 1) in-hospital and one-year mortality, 2) CDI incidence were assessed using logistic regression models.

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 (Respective Odds Ratio (95% Confidence Interval), OR (95%CI): 1.95 (1.06-3.58) and 2.02 (1.43-7.31)). High number of antibiotics (Per antibiotic, OR (95%CI): 1.89 (1.18-3.06)), rather than antibiotics duration (Per day, OR 95%CI): 1.04 (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 (95%CI): 0.43 (0.19 -0.99)) CONCLUSION: In older inpatients, CDI highly increase the burden of AP at both short and long term. If confirmed, these results suggest the preferential use of penicillin + beta-lactamase inhibitors for a lower incidence of CDI in older inpatients with AP.