Prevalence of six respiratory pathogens among children in Chengdu, China: a multiplex PCR-based detection study

Chenggui Liu^1*Jiuda Li¹Yao Deng¹Qin Wang²Xuemei Wang¹Shuzhe Yang¹Weijun He¹Zhiyong Liao¹

• ¹Chengdu Women's and Children's Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
• ²Sichuan Province Orthopedic Hospital, Chengdu, China

Background: Respiratory tract infections among children are commonly caused by various pathogens, and their prevalence varies across different groups. The objective is to investigate the prevalence of Influenza A virus (Flu A), Influenza B virus (Flu B), respiratory syncytial virus (RSV), Adenovirus (ADV), Rhinovirus (RV), and Mycoplasma pneumoniae (MP) among children in different groups in Chengdu and analyze their differences. Methods: This retrospective cross-sectional study included 39,190 children, with 21,847 males and 17,343 females. All respiratory specimens from the participants were tested for Flu A, Flu B, RSV, ADV, RV, and MP using multiplex PCR. Results: The overall prevalence of single infection, double co-infection, and triple co-infection was 48.19%, 7.09%, and 0.25%, respectively. The pathogen-specific prevalence from highest to lowest was RV (21.43%), ADV (16.69%), MP (11.73%), RSV (8.12%), Flu A (3.78%), and Flu B (1.37%). There were significant differences in the prevalence of the six pathogens across all six age groups (all p<0.001). The prevalence of Flu A, Flu B, ADV, and MP was highest in school-aged children and lowest in newborns; RSV prevalence peaked in infants and was lowest in adolescents; RV was most prevalent in toddlers and least in newborns. The prevalence of Flu A, Flu B, and RSV was significantly higher in spring/winter than in summer/autumn (p<0.001). MP and RV prevalence was significantly higher in spring/summer than in autumn/winter (p<0.001), while ADV prevalence was significantly higher in autumn/summer than in winter/spring (p<0.001). Among the five clinical diagnosis groups, Flu A and Flu B prevalence was highest in SRLT and lowest in CRDs; RSV and MP peaked in ALRTIs and bottomed in AURTIs; RV was highest in CRDs and lowest in AURTIs; ADV was highest in AURTIs and lowest in CRDs. Conclusions: Over half of the children were infected with at least one of the six respiratory pathogens, with RV, ADV, and MP being predominant. While co-infections were less common than single infections, they still occurred, with double co-infections being the main form. Notably, the prevalence varied significantly by age, season, and clinical diagnosis. These findings may offer useful references for developing targeted prevention and control strategies.