Severe community-acquired pneumonia and positive urinary antigen test for S. pneumoniae: amoxicillin is associated with a favourable outcome

Abstract

Positive urinary antigen tests (UAT) for pneumococcal infection in community-acquired pneumonia (CAP) may lead to targeted antibiotic therapy. We report an audit aimed at defining the link between mortality and targeted therapy. We conducted a retrospective multicentre audit of patients with severe CAP for whom a UAT was positive for S. pneumoniae. Patients admitted from January 2010 to December 2013 to 8 medical centres (from A to H) were included. Co-morbidities were defined by the specific treatment administered before hospital care, or if the diagnosis was newly established during the hospital stay. We used the Pneumonia Severity Index (PSI) to assess disease severity. Only patients with PSI > 90 were included. Antibiotic treatments and the PSI were extracted from patients' charts. Amoxicillin had to be prescribed as a targeted antibiotic treatment or at the time of antibiotic reassessment. A total of 389 patients were included. The mean (±STD) PSI score was 128 ± 29; 38.9% of the patients had a class 5 PSI score. Intensive care was required for 36.6% of the patients. Amoxicillin was initially prescribed in 47 cases (12.1%) and in 34 cases after reassessment (8.7%). In logistic regression analysis, we found three parameters associated with mortality: being hospitalised in institution D, class 5 PSI score, and metastatic cancer. In contrast, three antibiotic regimens were protective factors, including targeted therapy: OR = 0.09, p < 0.001. In the context of severe CAP with positive UAT for S. pneumoniae, targeted therapy was associated with a reduction in mortality.