# Changing patterns of respiratory pathogens in hospitalized children with community-acquired pneumonia in northern China following the lifting of non-pharmaceutical interventions

## TL;DR

This study shows that lifting pandemic restrictions in northern China led to increased detection of respiratory pathogens and more co-infections in hospitalized children with pneumonia.

## Contribution

The study reveals significant shifts in respiratory pathogen patterns and co-infection rates in children following the relaxation of pandemic control measures.

## Key findings

- Pathogen detection rates increased from 74.2% in 2022 to 86.5% in 2023 after NPIs were lifted.
- Co-infection rates rose from 25.1% to 45.1%, with more viral-bacterial co-infections observed.
- An age shift was noted, with older children showing higher RSV prevalence post-NPI lifting.

## Abstract

An observational, single-center study was conducted among hospitalized
children with community-acquired pneumonia in the Baoding area. The
objective was to compare the respiratory pathogen profiles and
epidemiological patterns during and after the lifting of non-pharmaceutical
interventions (NPIs, including mask-wearing, social distancing, lockdowns,
etc.). A total of 9,362 hospitalized children diagnosed with CAP in Baoding
from January 2022 to December 2023 were included. Both viral and bacterial
pathogens were detected by multiplex PCR. The NPIs were lifted in Baoding
from 2 December 2022. A comparative analysis was conducted on demographic
data, epidemiological data, pathogen detection rates, and co-infection
patterns that were compared between the full year 2022 and 2023. The
detection rate of at least one pathogen significantly increased from 74.2%
(2,925/3,940) in 2022 to 86.5% (4,690/5,422) in 2023 (P
< 0.001). Mycoplasma pneumoniae,
Streptococcus pneumoniae, human rhinovirus, respiratory
syncytial virus (RSV), and Haemophilus influenzae were the
predominant pathogens. Notably, co-infection rates rose from 25.1%
(988/3,940) in 2022 to 45.1% (2,445/5,422) in 2023 (P
< 0.001), particularly viral-bacterial co-infections. The positive
detection rates for many pathogens among severe pneumonia cases increased.
Additionally, an age shift in infection patterns was observed, with older
children showing a higher prevalence of RSV. Following the lifting of NPIs,
an increase in the detection rates of pathogens was observed, as were
fluctuations in the dynamics of viral and bacterial pathogens, underscoring
the urgent need to adapt clinical management and public health policies to
address emerging infection trends.

Community-acquired pneumonia (CAP) remains the leading infectious cause
of death in children worldwide. Understanding the pathogens responsible
for CAP is essential for effective diagnosis and treatment. This study
examines the changes in respiratory pathogens and epidemiological
patterns in children with CAP in Baoding, China, before and after the
lifting of non-pharmaceutical interventions (NPIs). Data from 9,362
children diagnosed with CAP from January 2022 to December 2023 were
analyzed. The detection rate of at least one pathogen increased
significantly from 74.2% in 2022 to 86.5% in 2023. Notably, co-infection
rates rose from 25.1% to 45.1%, with viral-bacterial co-infections being
more common. This research underscores the urgent need to adapt clinical
management and public health policies to address the changing infection
trends, highlighting their importance and innovation in understanding
the impact of NPIs on pediatric respiratory infections.