Objective:To analyze the distribution and epidemiological characteristics of common non-bacterial pathogens in hospitalized children with acute respiratory tract infections(ARTI)from a multi-center study covering 4 regions in Fujian Province in 2023.Methods:A retrospective cohort study was conducted using medical record analysis.A total of 22 769 hospitalized children with ARTI were enrolled from January to December 2023 across seven regional pediatric medical centers in Fujian Province (covering four major geographical divisions of Fuzhou, Nanping, Sanming and Longyan; all selected hospitals were regional children′s medical centers).Using single-tube multiplex PCR with fragment analysis on a Sanger sequencing platform, the nucleic acids of 11 common non-bacterial respiratory pathogens were tested in nasopharyngeal swabs collected from 22 769 children. These pathogens included influenza A virus(FluA), influenza B virus(FluB), parainfluenza virus(PIV), respiratory syncytial virus (RSV), adenovirus (ADV), human rhinovirus (HRV), human bocavirus (HBoV), human coronavirus (HCoV), human metapneumovirus(HMPV), Mycoplasma pneumoniae(MP), and Chlamydia (Ch). Count data were described as [ n(%)], and the chi-square test/Fisher′s exact test was used to compare the differences in rates between groups. Epidemiological features, including positive detection rates, pathogen profiles, and correlations with region, sex, age and month, were analyzed. Results:Among 22 769 children with ARTI, pathogens were detected in 16 213 cases (71.21%), including 13 340 single infections (58.59%).The detection rates of single pathogens in descending order were human rhinovirus (HRV, 12.95%), Mycoplasma pneumoniae(MP, 12.27%), respiratory syncytial virus(RSV, 11.12%), influenza A virus (Flu-A, 7.98%), parainfluenza virus(PIV, 4.66%), human metapneumovirus(HMPV, 4.60%), adenovirus(ADV, 2.70%), human bocavirus(HBoV, 0.84%), human coronavirus(HCoV, 0.82%), influenza B virus(Flu-B, 0.47%) and Chlamydia(Ch, 0.18%).Mixed infections occurred in 2 873 cases(12.62%), primarily dual infections(2 679 cases).Regional analysis revealed significant disparities:Luoyuan County Hospital (Fuzhou) exhibited the highest total detection rate(86.59%, 1 414/1 633)and mixed infection rate(23.27%, 380/1 633)(both P<0.001), with notably elevated MP (26.39%, 431/1 633);Jian′ou City Hospital(Nanping) ranked second for Flu-A(14.21%, 409/2 879), RSV(13.20%, 380/2 879) and mixed infections(17.12%, 493/2 879);Lianjiang County Hospital(Fuzhou) showed distinct prevalence of Flu-A(10.68%, 130/1 217), PIV(6.00%, 73/1 217), and HBoV(1.73%, 21/1 217); Yong′an City Hospital (Sanming) reported high MP (26.07%, 238/913) and RSV(12.38%, 113/913);Shaowu City Hospital(Nanping) was dominated by MP (18.60%, 407/2 188) and HRV(13.39%, 293/2 188); Tingzhou Hospital(Longyan) had the highest HRV (17.88%, 407/2 276) and Flu-B (0.75%, 17/2 276); and Fuzhou Children′s Hospital showed elevated ADV(3.38%, 394/11 663) and HCoV(1.08%, 126/11 663). Except for Flu-B(0.47%, 108/22 769; P=0.054) and Ch(0.18%, 40/22769; P=0.900), all pathogens and mixed infections exhibited significant regional variations ( P<0.05).Gender analysis indicated higher detection rates of HRV, RSV, Flu-A, ADV, PIV, HBoV and mixed infections in males, while MP, HMPV, Flu-B, HCoV, and Ch were more prevalent in females, with statistically significant differences for HRV and MP (both P<0.001). Age stratification showed the highest overall detection rate in the 3-<6 years group (75.48%; P<0.001): RSV and Ch peaked in infants (<1 year), HRV, PIV, ADV and HBoV in toddlers (1-<3 years), HMPV, HCoV, and mixed infections in preschool children (3-<6 years), and MP, Flu-A and Flu-B in older children (6-<18 years).Analyzing the prevalent months, the monthly prevalence trends of pathogens in various regions are similar.Seasonal trends demonstrated year-round HRV activity (peaking in spring/autumn), MP prevalence in autumn/winter, RSV surges in spring-summer (April-June) and late summer-autumn (August-October), and Flu-A predominanced in winter-spring. Conclusion:Multiplex PCR with fragment analysis demonstrated high diagnostic efficacy. The top 4 non-bacterial pathogens in Fujian Province′s ARTI-hospitalized children in 2023 were HRV, MP, RSV and Flu-A. Pathogen distribution exhibited significant regional, age and seasonal variations, emphasizing the need for targeted prevention strategies.

Objective:To analyze the distribution and epidemiological characteristics of common non-bacterial pathogens in hospitalized children with acute respiratory tract infections(ARTI)from a multi-center study covering 4 regions in Fujian Province in 2023.Methods:A retrospective cohort study was conducted using medical record analysis.A total of 22 769 hospitalized children with ARTI were enrolled from January to December 2023 across seven regional pediatric medical centers in Fujian Province (covering four major geographical divisions of Fuzhou, Nanping, Sanming and Longyan; all selected hospitals were regional children′s medical centers).Using single-tube multiplex PCR with fragment analysis on a Sanger sequencing platform, the nucleic acids of 11 common non-bacterial respiratory pathogens were tested in nasopharyngeal swabs collected from 22 769 children. These pathogens included influenza A virus(FluA), influenza B virus(FluB), parainfluenza virus(PIV), respiratory syncytial virus (RSV), adenovirus (ADV), human rhinovirus (HRV), human bocavirus (HBoV), human coronavirus (HCoV), human metapneumovirus(HMPV), Mycoplasma pneumoniae(MP), and Chlamydia (Ch). Count data were described as [ n(%)], and the chi-square test/Fisher′s exact test was used to compare the differences in rates between groups. Epidemiological features, including positive detection rates, pathogen profiles, and correlations with region, sex, age and month, were analyzed. Results:Among 22 769 children with ARTI, pathogens were detected in 16 213 cases (71.21%), including 13 340 single infections (58.59%).The detection rates of single pathogens in descending order were human rhinovirus (HRV, 12.95%), Mycoplasma pneumoniae(MP, 12.27%), respiratory syncytial virus(RSV, 11.12%), influenza A virus (Flu-A, 7.98%), parainfluenza virus(PIV, 4.66%), human metapneumovirus(HMPV, 4.60%), adenovirus(ADV, 2.70%), human bocavirus(HBoV, 0.84%), human coronavirus(HCoV, 0.82%), influenza B virus(Flu-B, 0.47%) and Chlamydia(Ch, 0.18%).Mixed infections occurred in 2 873 cases(12.62%), primarily dual infections(2 679 cases).Regional analysis revealed significant disparities:Luoyuan County Hospital (Fuzhou) exhibited the highest total detection rate(86.59%, 1 414/1 633)and mixed infection rate(23.27%, 380/1 633)(both P<0.001), with notably elevated MP (26.39%, 431/1 633);Jian′ou City Hospital(Nanping) ranked second for Flu-A(14.21%, 409/2 879), RSV(13.20%, 380/2 879) and mixed infections(17.12%, 493/2 879);Lianjiang County Hospital(Fuzhou) showed distinct prevalence of Flu-A(10.68%, 130/1 217), PIV(6.00%, 73/1 217), and HBoV(1.73%, 21/1 217); Yong′an City Hospital (Sanming) reported high MP (26.07%, 238/913) and RSV(12.38%, 113/913);Shaowu City Hospital(Nanping) was dominated by MP (18.60%, 407/2 188) and HRV(13.39%, 293/2 188); Tingzhou Hospital(Longyan) had the highest HRV (17.88%, 407/2 276) and Flu-B (0.75%, 17/2 276); and Fuzhou Children′s Hospital showed elevated ADV(3.38%, 394/11 663) and HCoV(1.08%, 126/11 663). Except for Flu-B(0.47%, 108/22 769; P=0.054) and Ch(0.18%, 40/22769; P=0.900), all pathogens and mixed infections exhibited significant regional variations ( P<0.05).Gender analysis indicated higher detection rates of HRV, RSV, Flu-A, ADV, PIV, HBoV and mixed infections in males, while MP, HMPV, Flu-B, HCoV, and Ch were more prevalent in females, with statistically significant differences for HRV and MP (both P<0.001). Age stratification showed the highest overall detection rate in the 3-<6 years group (75.48%; P<0.001): RSV and Ch peaked in infants (<1 year), HRV, PIV, ADV and HBoV in toddlers (1-<3 years), HMPV, HCoV, and mixed infections in preschool children (3-<6 years), and MP, Flu-A and Flu-B in older children (6-<18 years).Analyzing the prevalent months, the monthly prevalence trends of pathogens in various regions are similar.Seasonal trends demonstrated year-round HRV activity (peaking in spring/autumn), MP prevalence in autumn/winter, RSV surges in spring-summer (April-June) and late summer-autumn (August-October), and Flu-A predominanced in winter-spring. Conclusion:Multiplex PCR with fragment analysis demonstrated high diagnostic efficacy. The top 4 non-bacterial pathogens in Fujian Province′s ARTI-hospitalized children in 2023 were HRV, MP, RSV and Flu-A. Pathogen distribution exhibited significant regional, age and seasonal variations, emphasizing the need for targeted prevention strategies.