Pneumococcal Detection and Bacterial Co-Detection in Children After COVID-19: A Two-Year Multiplex PCR Study

Background: Non-pharmaceutical interventions during the COVID-19 pandemic altered respiratory pathogen circulation, and a bacterial rebound followed once restrictions were lifted. We describe pediatric pneumococcal respiratory infections and their bacterial co-detections in the immediate post-pandemic period. Methods: We retrospectively analyzed respiratory specimens from children aged 0-18 years tested with a multiplex real-time PCR panel (Allplex Respiratory Panel, Seegene, Seoul, South Korea; seven bacterial pathogens) restricted to this predefined bacterial spectrum at a tertiary pediatric hospital in Galați, Romania, during 2022 and 2023. A total of 2546 panels were performed in 2022 and 3250 in 2023, allowing pneumococcal positivity rates to be calculated. Proportions are reported with Wilson 95% confidence intervals; associations were tested with Pearson chi-square and Fisher exact tests in SPSS v.23. Results: Children with detected Streptococcus pneumoniae rose from 100 to 415, corresponding to a rise in pneumococcal positivity from 3.9% (100/2546) to 12.8% (415/3250). Among the positive children, pneumococcus-Haemophilus influenzae co-detection increased from 33.0% to 45.1% (odds ratio 1.63, 95% CI 1.02-2.61; p = 0.029), while pneumococcus alone fell from 60.0% to 50.1%. Boys, urban residence, and early childhood predominated, and community-acquired pneumonia diagnoses rose from 61 to 214. No profile-demographic association reached significance (panel-residence 2023, p = 0.063). Conclusions: A post-pandemic rise in pediatric pneumococcal detections and increasing H. influenzae co-detection were observed, supporting syndromic multiplex PCR in rapid pediatric diagnostics and antimicrobial stewardship.