Invasive Pneumococcal Disease in Children: A Retrospective Three-Center Study in Zhejiang Province, China (2010–2024)

Invasive pneumococcal diseases (IPD) are among the leading causes of global child mortality. Pneumococcal conjugate vaccines provide direct protection against IPD caused by serotypes included in the vaccine. To investigate the clinical characteristics, serotypes, and antibiotic resistance of Streptococcus pneumoniae (SP) causing IPD in children in China. Clinical data of IPD in children from three hospitals in Zhejiang Province, China, between January 2010 and September 2024 were retrospectively analyzed. Serotyping of SP was performed using the Quellung reaction, and antimicrobial susceptibility testing was conducted via the E-test method. A total of 295 patients with IPD were identified, with ages ranging from 17 days to 13 years. Among them, 241 (81.7%) were children under 5 years old. The prevalent diagnoses included bacteremic pneumonia (33.2%), bacteremia without focus (27.1%), and meningitis (23.4%). Multiple organ damage or failure occurred in 73 patients (24.7%), pleural effusion/pyopneumothorax in 32 patients (10.8%), and septic shock in 22 patients (7.5%). There were 130 patients (44.1%) with underlying diseases, and leukemia was the most prevalent (41 patients). Sixteen patients (5.4%) died, including seven patients of purulent meningitis. Among 198 serotyped isolates, the ‌overall PCV13 serotype coverage rate‌ was 84.3%. The five most common serotypes were 19F (28.8%), 14 (13.6%), 6B (10.6%), 19A (9.6%), and 23F (9.1%). Forty-one (20.7%) isolates were resistant to penicillin, and 13.6% resistant to ceftriaxone. Serotypes 19F, 6B, and 19A exhibited significantly higher multidrug resistance rates than other serotypes ( P < 0.001). IPD is most prevalent in children under 5 years of age and children with underlying medical conditions, with bacteremic pneumonia, bacteremia without focus, and meningitis as the main clinical manifestations. PCV13 serotypes remain the most common serotypes causing IPD in this region.