COVID-19 Pandemic Alters Epidemiological Trends of Respiratory Diseases in Children

A study published in Frontiers in Microbiology reveals significant changes in the epidemiological profile of respiratory diseases in children in Chengdu, China, before, during, and after the COVID-19 pandemic. Between 2017 and 2024, researchers analyzed clinical diagnoses and antibody test results from 222,364 children treated in a hospital. The study found an overall upward trend in antibody positive rates with three epidemic peaks, a notable decline during the pandemic, and shifts in respiratory disease composition among antibody-positive children.

Key Takeaways:

• The study found a significant increase in antibody positive rates among children in Chengdu, China, starting in 2023, with an overall upward trend between 2017 and 2024.
• Females showed higher susceptibility to the pathogen than males, with outpatients aged 3-6 years and inpatients aged 0-3 years being most vulnerable pre-pandemic.
• Post-pandemic, antibody positive rates increased with age (0-6 years), and seasonal peaks shifted from autumn to winter-autumn alternation during the mid-to-late pandemic.
• Early-pandemic humidity positively correlated with antibody positive rates, while post-pandemic asthma replaced post-infection cough as the third most common outpatient diagnosis.
• Inpatient diagnoses were dominated by pneumonia and severe pneumonia, with a significant rise in proportion post-pandemic.

Statistics:

• 222,364 children were analyzed in the study.
• The study found three epidemic peaks in antibody positive rates: 2017, 2019, and 2023-2024.
• 113 cases of severe pneumonia were reported in 2024, a significant rise from previous years.
• The study found a positive correlation between early-pandemic humidity and antibody positive rates.
• Post-pandemic, asthma accounted for 4.5% of outpatient diagnoses, replacing post-infection cough as the third most common diagnosis.

Sources:

• "Positive rates of Mycoplasma pneumoniae antibodies in children before, during and after COVID-19 outbreak: an observational study in Chengdu, China from 2017 to 2024."
• Frontiers in Microbiology, 2025;16:1649615.
• Hao Dong, Chengdu Women's and Children's Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, People's Republic of China.
• Frontiers Media Sa, Avenue Du Tribunal Federal 34, Lausanne, Ch-1015, Switzerland.