Decreased relative risk of pneumococcal pneumonia during the last decade, a nested case-control study.

Background: (SP) is one of the most common pathogens of Community-Acquired Pneumonia (CAP), but recent reports suggest that its incidence may be declining in relation to the use of the conjugate 13-valent pneumococcal vaccine in children. We compared the result of the immunochromatographic SP urinary antigen test (SPUAT) and clinical outcomes in patients with CAP admitted in two periods of time: 2001-2002(CAP1) and 2015-2016(CAP2).

Methods: This was a matched nested case-control study of two prospectively recorded cohorts of patients admitted with CAP, with SPUAT and blood culture performed in all patients.