Pneumococcal Pneumonia in Hospitalized Children: 2017-2023.

OBJECTIVES We hypothesized that the incidence, clinical presentation, isolate serotypes, and isolate antibiotic susceptibility of Streptococcus pneumoniae causing pneumonia in children varied before and through the course of the COVID-19 pandemic. METHODS Patients aged 18 years or younger at 8 children's hospitals in the United States admitted with culture-positive pneumonia were identified. Serotyping of pneumococcal isolates was performed at a central research laboratory. Clinical and laboratory data were collected retrospectively with a standardized case report form. RESULTS We identified 190 patients with pneumococcal pneumonia from 2017 to 2023. Cases decreased significantly in 2020 (P < .05), with a surge in 2022 and 2023. Serotype 3 was the most common serotype, was prominent after 2021, and was associated with a significantly higher rate of empyema and necrotizing parenchyma (P < .001). PCV13 serotypes 3, 19A, and 19F constituted over half of isolates; new serotypes in PCV15 (22F and 33F) and PCV20 (8, 10A, 11A, 12F, 15B, 22F, and 33F) accounted for 14% and 22% of isolates, respectively. Penicillin susceptibility (minimum inhibitory concentration [MIC] ≤ 2 μg/mL) was very common (94% of isolates), and all 11 isolates with MIC greater than 2 μg/mL were serotype 19A. Of those tested, 90 patients had viral coinfections; only influenza was associated with more pneumonia complications compared with patients without influenza (P = .002). CONCLUSIONS S pneumoniae remains an important cause of pneumonia in children with the potential for severe infections. After 2020, increasing rates have primarily been due to serotype 3, while β-lactam resistance was largely associated with serotype 19A. PCV15 and PCV20 may modestly reduce pneumococcal pneumonia incidence further.