Changes in Spectrum of Respiratory Pathogen Infections and Disease Severity Among Children in Hohhot: Impact of COVID-19 Prevention Measures (preprint)

ABSTRACT

Background Acute respiratory infections (ARIs) are caused by various pathogens, and the outbreak of the novel coronavirus has led to changes in the patterns of respiratory pathogen infections. Through long-term study of respiratory tract infection data in children from Hohhot, significant differences in the spectrum of respiratory pathogen infections, disease severity, and seasonal patterns have been discovered between 2022 and 2023.Methods Throat swabs were collected from 605 children with ARIs at the First Hospital of Hohhot, and pathogen detection was performed using microarray technology. Blood biomarkers, symptoms, and clinical diagnoses were evaluated.Results The study found that 56.03% of the patients were male, with an average age of 3.45 years. Pathogen dynamics revealed that SARS-CoV-2 was the most prevalent infection, accounting for 262 cases. It persisted from October 2022 to January 2023 and then disappeared. Influenza A virus (IAV) cases peaked in March 2023. Respiratory syncytial virus (RSV), Influenza B virus (IBV), Parainfluenza virus (PIV), Mycoplasma pneumoniae (M. pneumoniae), Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Group A streptococcus (GAS) were not detected after December 2022. The proportion of mixed infections was 41.94% among SARS-CoV-2 patients, while other pathogens had mixed infection rates exceeding 57.14%. Before December 2022, the mean value of white blood cell (WBC) count for Streptococcus pneumoniae (S. pneumoniae), Haemophilus influenzae (H. influenzae), Epstein-Barr virus (EBV), and Cytomegalovirus (CMV) was 8.83*10^9/L, C-reactive protein (CRP) was 18.36 mg/L, and procalcitonin (PCT) was 1.11 ng /ml. After December 2022, these values decreased to 5.5*10^9/L, 6.33 mg/L, and 0.24 ng /ml, respectively. Similarly, the proportion of patients with cough, difficulty breathing, and running nose, as well as the diagnosis of lower respiratory tract infections, decreased in December 2022. However, the situation was different for SARS-CoV-2 infections.Conclusions Strict SARS-CoV-2 policies reduced the infection risk for S. pneumoniae, H. influenzae, EBV, and other pathogens before November 2022. However, patient symptoms worsened compared to after November 2022, possibly due to an excessive focus on SARS-CoV-2, neglecting other diseases, and reduced population immunity to respiratory infections.