C-reactive protein to rule out complicated pneumococcal disease manifestations: a retrospective cohort study in adults with pneumococcal bacteraemia.

OBJECTIVES: To explore the negative predictive value (NPV) of C-reactive protein (CRP) at admission to exclude complicated disease manifestations of pneumococcal disease. METHODS: A Dutch multicentre retrospective cohort study was conducted between 01-01-2012 and 30-06-2020. Adults with positive blood cultures for Streptococcus pneumoniae, whose CRP was measured at admission and whose infection focus was known, were included. Electronic medical and microbiological records were reviewed. RESULTS: Of the 832 bacteraemic patients enrolled, 30% had complicated manifestations of pneumococcal disease; most frequent were pleural effusion (8.9%), pleural empyema (5.4%) and meningitis (7.5%). Compared to solitary pneumonia, patients with pleural effusion and empyema presented with higher CRP levels. Although low CRP levels did not exclude complicated disease in general, a CRP level < 114 mg/L at admission could reliably exclude empyema among adult pneumonia patients with an NPV of 93% and a specificity of 26%. However, in cases where pleural fluid was present, CRP levels were mostly > 114 mg/L, such that suspicion of empyema could only be ruled out in a minority of cases (10%). CONCLUSIONS: Complicated manifestations are prevalent in adult pneumococcal bacteraemia. Low blood CRP levels can reliably exclude the development of pulmonary empyema. Practical value may be largest in settings without thoracic imaging at hand.

The drop in reported invasive pneumococcal disease among adults during the first COVID-19 wave in the Netherlands explained.

OBJECTIVES: Streptococcus pneumoniae is the leading bacterial pathogen causing respiratory infections. Since the COVID-19 pandemic emerged, less invasive pneumococcal disease (IPD) was identified by surveillance systems worldwide. Measures to prevent transmission of SARS-CoV-2 also reduce transmission of pneumococci, but this would gradually lead to lower disease rates. DESIGN: Here, we explore additional factors contributing to the instant drop in pneumococcal disease cases captured in surveillance. RESULTS: Our observations on referral practices and other impediments to diagnostic testing indicate that residual IPD has likely occurred but remained undetected by conventional hospital-based surveillance. CONCLUSIONS: Depending on the setting, we discuss alternative monitoring strategies that could improve understanding of pneumococcal disease dynamics.