Community-acquired pneumonia (CAP) is the leading infectious cause of childhood mortality. Although Streptococcus pneumoniae is the most common agent, its detection by culture is uncommon. Complicated CAP (cCAP) includes manifestations such as pleural effusion, empyema, lung necrosis and abscess. As a severe condition associated with prolonged hospitalization, understanding the clinical and microbiological profile of these patients is essential to guide treatment and improve outcomes.

To analyze the clinical and microbiological profile of patients with cCAP with isolation of S. pneumoniae in a pediatric-only hospital in southern Brazil.

Analytical, observational, cross-sectional and non-interventional study with data collection from medical records of patients diagnosed with cCAP and positive sterile-site cultures for S. pneumoniae, hospitalized between July 2021 and July 2024. The study was approved by the Ethics Committee (CAAE 7.116.953).

We identified 43 patients with CAP and isolation of S. pneumoniae, of whom 32 (74.4%) had complications, mainly pleural effusion. Procedures such as drainage were performed in 30 cases, and 15 had lung necrosis. The mean age was 40 months; 65% (n=21) of patients were treated under the public health system (SUS). Among the 30 patients who underwent drainage, the pathogen was isolated from pleural fluid in 16 (53%) patients, only from blood in 9 (30%) patients, and from both samples in 5 (17%). Of the 32 cCAP cases, 25 (78%) required ICU admission (for an average of 8 days). Regarding penicillin susceptibility, 15% were susceptible, 62.5% showed susceptible-increased exposure (I) and 21.8% were resistant. For ceftriaxone, there was no resistance: 66% were I and 34% susceptible. All isolates were susceptible to vancomycin. The serotypes identified in complicated cases were: 19A (47%; n=15), 3 (13%; n=4), all with necrosis, 14 (9%; n=3), 6C (6%; n=2), 15B (3%; n=1), 15F (3%; n=1); in 6 cases (19%), serotype was not identified.

cCAP due to S. pneumoniae predominantly affects children under 5 years of age, with a high frequency of invasive interventions and variability in susceptibility profiles. Serotype 19A was the most common, underscoring the importance of microbiological surveillance and adequate vaccine coverage.