Pneumococcal community-acquired pneumonia is frequently complicated by parapneumonic pleural effusion. In Belgium, three pneumococcal conjugate vaccines were introduced between 2007 and 2019. These are successively the heptavalent (PCV7), the 13-valent (PCV13) and the 10-valent (PCV10) pneumococcal conjugate vaccine. Our aim was to assess the effect of pneumococcal conjugate vaccines over time on the incidence of parapneumonic pleural effusion during the pre-vaccination (pre-PCV) and the three vaccination periods.
The demographic and clinical-biological characteristics of hospitalized children with pleural effusion complicating community-acquired pneumonia were collected retrospectively between January 2000 and August 2019.
Among 474 children hospitalized for pneumonia with pleural effusion, Streptococcus pneumoniae was detected in 140 bacteriological samples. During the study period, the overall incidence of parapneumonic pleural effusion increased by 50.8% during the PCV10 period (p<0.0001). The incidence of pneumococcal pleural effusion was 27.2‰ during the PCV10 period and increased by approximately 60% compared to the pre-PCV period (p=0.0005) with a moderate decrease during the PCV13 period.
Our study observes an increasing incidence of pleural effusions in children with pneumonia after the introduction of pneumococcal conjugate vaccines in Belgium. The reasons of these increased incidences remain unclear and should be confirmed in larger series of children. Pneumococcal vaccination in children remains however highly recommended by its favorable outcome on overall invasive pneumococcal disease.