In recent years, data from CDC surveillance and paediatric clinics suggest that the prevalence of respiratory infections in children has changed compared with the past, that regional prevalence statistics are of directional significance for the diagnosis and treatment of respiratory infections in children, and that large sample analyses of the epidemiology of children's respiratory pathogens in the northeast region of Sichuan Province are still rare.

To ascertain the prevalence of 13 respiratory non-bacterial pathogens in children in three areas of northeastern Sichuan Province (Bazhong, Nanchong and Guang'an) following the outbreak, with a view to providing a basis for the prevention and treatment of respiratory infections in clinical children.

A retrospective analysis of pathogen samples from 15 772 children diagnosed with acute respiratory tract infections and hospitalised in Bazhong Central Hospital, Nanchong Central Hospital and Guang'an People's Hospital between 7 December 2022 and 30 June 2024 was conducted. Of these, 8 707 (55.2%) were male and 7 065 (44.8%) were female. The subjects were divided into four groups according to their age groups: infant group (<1 year old), 3 938 cases; toddler group (1-<3 years old), 6 434 cases; preschool group (3-<6 years old), 3 231 cases; and school-age group (6-14 years old), 2 169 cases. The onset of the disease was categorised according to the season, with 15 772 cases divided as follows: 5 423 cases in the spring (March to May), 2 594 cases in the summer (June to August), 3 121 cases in the autumn (September to November) and 4 634 cases in the winter (December to February). A total of 13 non-bacterial pathogens, including influenza A virus, influenza A virus H1N1, influenza A virus H3N2, influenza B virus, parainfluenza virus, Mycoplasma pneumoniae, chlamydia, parapneumovirus, respiratory syncytial virus, adenovirus, rhinovirus, bocavirus and coronavirus, were detected using the multiplex reverse transcription polymerase chain reaction technique. The subsequent investigation focused on the detection of pathogens in the total sample, with the positive detection rate of each pathogen being compared among different regions, genders, age groups and seasons.

Of the 15 772 respiratory samples, 11 618 (73.66%) were positive for pathogens, while 3 632 (23.03%) were identified as mixed infections. The most prevalent pathogens identified were rhinovirus (24.5%), respiratory syncytial virus (16.4%), Mycoplasma pneumoniae (13.8%), influenza A virus (9.4%) and parainfluenza virus (8.9%). The total detection rates of pathogens in samples from the Bazhong, Nanchong and Guang'an regions were 80.9%, 73.7%, and 75.3%, respectively. The difference in the total detection rates of pathogens in samples from the three regions was statistically significant when comparing the rates of pathogens in samples from the three regions (χ²=101.119, P<0.001). The total detection rate of pathogens in samples from boys (72.1%) was lower than that of girls (75.6%) (χ²=24.539, P<0.001). However, among the 13 pathogens, except for coronavirus, the differences in the detection rates were not statistically significant when compared among different genders (P>0.05). A statistically significant difference was observed when the total detection rates of pathogens in samples from the infant, toddler, preschool and school-age groups were compared (χ²=174.613, P<0.001). Among the 13 pathogens, with the exception of coronavirus, statistically significant differences were identified when the detection rates of the remaining pathogens were compared among different age groups (P<0.05). Furthermore, a comparison of the total detection rates of pathogens in samples collected during different seasons (spring, summer, autumn and winter) revealed a statistically significant difference (χ²=364.584, P<0.001). Notably, the winter samples exhibited the highest total detection rate of pathogens (80.0%), while the spring samples exhibited the lowest (72.3%) .

The main pathogens of acute respiratory infections in children in the three regions of northeast Sichuan were rhinovirus, respiratory syncytial virus, Mycoplasma pneumoniae, influenza A virus and parainfluenza virus, and the epidemiology varied by region. Among the 13 pathogens, except for coronaviruses, there was no difference in the detection rate among different genders but there were differences between age and seasonal subgroups.

近年来，来自疾控监测及儿科临床的数据均提示儿童呼吸道感染流行情况较既往有所变化，区域性流行情况的统计对于儿童呼吸道感染疾病诊治具有指向性意义，川东北地区目前尚较少见儿童呼吸道病原体流行病学的大样本分析。

了解四川省东北3个地区（巴中、南充、广安）儿童13种呼吸道非细菌性病原体的流行情况，为临床儿童呼吸道感染的预防与治疗提供依据。

回顾性分析2022-12-07—2024-06-30在巴中市中心医院、南充市中心医院、广安市人民医院住院的15 772例急性呼吸道感染患儿的病原体样本，其中男8 707例（55.2%）、女7 065例（44.8%）；按年龄段分为4组：婴儿组（<1岁）3 938例、幼儿组（1~<3岁）6 434例、学龄前期组（3~<6岁）3 231例、学龄期组（6~14岁）2 169例；按发病季节分为：春季（3—5月）5 423例、夏季（6—8月）2 594例、秋季（9—11月）3 121例、冬季（12月—次年2月）4 634例。采用多重反转录聚合酶链反应技术检测甲型流感病毒、甲型流感病毒H1N1病毒、甲型流感病毒H3N2病毒、乙型流感病毒、副流感病毒、肺炎支原体、衣原体、偏肺病毒、呼吸道合胞病毒、腺病毒、鼻病毒、博卡病毒和冠状病毒共13种非细菌性病原体。调查总样本病原体的检出情况，并比较各病原体在不同地区、不同性别、不同年龄组及不同季节的阳性检出率。

15 772例呼吸道样本中检出病原体阳性11 618例，检出率为73.7%；混合感染3 632例，占23.0%。总检出率前5位的病原体分别为鼻病毒（24.5%）、呼吸道合胞病毒（16.4%）、肺炎支原体（13.8%）、甲型流感病毒（9.4%）、副流感病毒（8.9%）。巴中地区、南充地区、广安地区样本病原体总检出率分别为80.9%、73.7%、75.3%；3个地区样本病原体总检出率比较，差异有统计学意义（χ²=101.119，P<0.001）。男童样本病原体总检出率（72.1%）低于女童（75.6%）（χ²=24.539，P<0.001）；13种病原体中除冠状病毒外，不同性别间其余病原体检出率比较差异均无统计学意义（P>0.05）。婴儿组、幼儿组、学龄前期组、学龄期组样本病原体总检出率比较，差异有统计学意义（χ²=174.613，P<0.001）；13种病原体中除冠状病毒外，不同年龄组其余病原体检出率比较差异均有统计学意义（P<0.05）。春、夏、秋、冬季样本病原体总检出率比较，差异有统计学意义（χ²=364.584，P<0.001）；其中冬季样本病原体总检出率最高（80.0%），春季样本病原体总检出率最低（72.3%）。

川东北3个地区儿童急性呼吸道感染的主要病原体为鼻病毒、呼吸道合胞病毒、肺炎支原体、甲型流感病毒和副流感病毒，且各地区流行情况不同。13种病原体中除冠状病毒外，不同性别间其余病原体检出率无差异，但年龄和季节分组间存在差异。