Work

Disruption and change in positivity of respiratory pathogen epidemiology in children during and after the COVID-19 pandemic, 2018–2023: a large-scale period-comparison study in Guangzhou, southern China

Year: 2026

Type: article

Abstract: Background Non-pharmaceutical interventions (NPIs) during the COVID-19 pandemic disrupted respiratory pathogen transmission, but post-pandemic change in positivity patterns across pathogens, age groups, and co-infections remain incompletely characterized in children. Methods We conducted a retrospective period-comparison study at two Guangzhou hospitals, encompassing 230,333 patient-period records (2018–2023). Using logistic regression, we compared adjusted odds ratios (aOR) for 16 pathogens across three pandemic periods (Pandemic-I: strict NPIs; Pandemic-II: relaxed NPIs; Post-pandemic: full reopening) versus pre-pandemic baseline, with age-period interactions tested by likelihood-ratio. Results Most respiratory viruses and M. pneumoniae were suppressed in Pandemic-I, with notable exceptions such as rhinovirus, CMV, and bocavirus (influenza A aOR = 0.23; B aOR = 0.08). Post-pandemic changes in test positivity diverged: influenza A showed increased positivity across all ages (aOR = 1.23–1.74); RSV showed increased positivity in children <5 years (aOR = 1.50–1.86); M. pneumoniae showed a marked increase in positivity in school-aged children (5–9 years: aOR = 3.32); influenza B remained suppressed in young children (aOR = 0.53–0.58) but showed increased positivity in adolescents (aOR = 2.88). Age-period interactions were significant for all four ( p < 0.001). Bacterial changes were modest and should be interpreted cautiously because culture positivity is influenced by specimen type, hospitalization, antibiotic exposure, and culture indications. Co-infections shifted from bacterial–bacterial dominance in Pandemic-I (49.0%) to bacterial–influenza co-infections post-pandemic (22.9%). Conclusion The pandemic reshaped pediatric respiratory pathogen epidemiology in pathogen- and age-specific ways, and may warrant consideration of age-stratified surveillance and tailored prevention.

Source: Frontiers in Microbiology

DOI: 10.3389/fmicb.2026.1992791