探讨2020至2024年遵义地区儿童社区获得性肺炎（CAP）的病原菌分布特征及其随年份、年龄和季节的变化规律，为临床经验性抗感染治疗提供依据。

回顾性收集遵义市5家医院住院治疗的细菌性病原体CAP患儿的临床资料，纳入痰培养阳性且符合CAP诊断标准的病例共21 546例，采用Pearson卡方检验分析不同发病年龄和季节病原菌构成特征，采用趋势卡方检验分析不同发病年份病原菌的分布。

共入组21 546例痰培养阳性儿童CAP患儿，其中男性患儿13 307例（61.8%），女性患儿8 239例（38.2%）；不同年份、季节、年龄分布差异均有统计学意义（χ²=1 103.4、1 083.9、3 733.9，P均＜0.001）。革兰阴性菌和革兰阳性菌检出率年份分布差异具有统计学意义（χ²=189.5、P＜0.001），2024年革兰阴性菌检出率反超革兰阳性菌（53.0% vs. 47.0%）。病原菌检出率前5位分别为流感嗜血杆菌（6 972例、32.4%）、肺炎链球菌（5 746例、26.7%）、金黄色葡萄球菌（3 825例、17.8%）、耐甲氧西林金黄色葡萄球菌（MRSA）（2 027例、9.4%）和大肠埃希菌（852例、4.0%）。年龄分布：婴儿组患儿以流感嗜血杆菌（3 344/11 073、30.2%）、金黄色葡萄球菌（2 702/11 073、24.4%）、大肠埃希菌（742/11 073、6.5%）感染为主；幼儿及学龄前患儿以肺炎链球菌[37.9%（2 228/5 879）和33.1%（1 217/3 672）]、流感嗜血杆菌[39.3%（2 308/5 879）和31.2%（1 145/3 672）]感染为主；学龄期患儿以MRSA检出率最高（348/922、37.7%）。季节分布：秋冬季细菌感染率较高，四季均以流感嗜血杆菌和肺炎链球菌为主，流感嗜血杆菌冬季检出率最高（2 627/6 238、42.1%），肺炎链球菌秋季占比最高（1 821/5 435、33.4%）。耐药性分析显示，流感嗜血杆菌对复方新诺明、氨苄西林、头孢呋辛高度耐药[耐药率分别为95.3%（6 644/6 972）、89.6%（6 247/6 972）和73.4%（5 142/6 972）]，大肠埃希菌对氨苄西林、头孢呋辛和头孢曲松耐药率分别为91.1%（752/825）、83.0%（685/825）和78.4%（647/825），二者对哌拉西林/他唑巴坦、美罗培南均敏感；肺炎链球菌对四环素耐药率为100%（5 746/5 746），金黄色葡萄球菌对青霉素耐药率为92%（3 519/3 825），MRSA对克林霉素和红霉素耐药率均＞90%，上述革兰阳性菌对万古霉素和利奈唑胺等均敏感。

本地区CAP患儿病原菌检出率存在明显的年份、季节和年龄差异，2024年革兰阴性菌检出率反超革兰阳性菌，不同年龄段优势致病菌不同且秋冬季感染高发，常见致病菌对多种常规抗菌药物耐药严重，需要根据药敏试验结果选择合理抗菌药物。

To investigate the distribution characteristics of pathogens causing community-acquired pneumonia (CAP) in children in Zunyi region from 2020 to 2024, and to analyze their variations by year, age and season, in order to provide evidence for empirical anti-infection therapy.

Clinical data of hospitalized children with bacterial CAP from five hospitals in Zunyi were collected, retrospectively. Total of 21 546 cases with positive sputum cultures and meeting CAP diagnostic criteria were included. The pathogen spectrum and its distribution across different years, age groups and seasons were analyzed. The characteristics of pathogen composition across different ages and seasons were analyzed by Pearson Chi-square test, and the pathogen distribution across different years was analyzed by Chi-square trend test.

Total of 21 546 children with CAP who had positive sputum cultures were enrolled, including 13 307 males (61.8%) and 8 239 females (38.2%). There were statistically significant differences in the distribution of children among different years, seasons and age groups (χ²=1 103.4, 1 083.9, 3 733.9; all P<0.001). The detection rates of Gram-negative bacteria and Gram-positive bacteria showed significant differences in distribution among different years (χ²=189.5, P<0.001), and the detection rate of Gram-negative bacteria (53.0%) exceeded that of Gram-positive bacteria (47.0%) in 2024. The top 5 pathogens in terms of detection rate were Haemophilus influenzae (6 972 cases, 32.4%), Streptococcus pneumoniae (5 746 cases, 26.7%), Staphylococcus aureus (3 825 cases, 17.8%), methicillin-resistant Staphylococcus aureus (MRSA) (2 027 cases, 9.4%) and Escherichia coli (852 cases, 4.0%). Age distribution: children in infant group were mainly infected with Haemophilus influenzae (3 344/11 073, 30.2%), Staphylococcus aureus (2 702/11 073, 24.4%) and Escherichia coli (742/11 073, 6.5%); children in the toddler and preschool group were mainly infected with Streptococcus pneumoniae [37.9% (2 228/5 879) and 33.1% (1 217/3 672)] and Haemophilus influenzae [39.3% (2 308/5 879) and 31.2% (1 145/3 672)]; children in the school-age group had the highest detection rate of MRSA (348/922, 37.7%). Seasonal distribution: the bacterial infection rate was higher in autumn and winter. Haemophilus influenzae and Streptococcus pneumoniae were the main pathogens in all four seasons, among which Haemophilus influenzae had the highest detection rate in winter (2 627/6 238, 42.1%) and Streptococcus pneumoniae had the highest proportion in autumn (1 821/5 435, 33.4%). Drug resistance analysis showed that Haemophilus influenzae was highly resistant to trimethoprim-sulfamethoxazole, ampicillin and cefuroxime [resistance rates were 95.3% (6 644/6 972), 89.6% (6 247/6 972) and 73.4% (5 142/6 972)]. The resistance rates of Escherichia coli to ampicillin, cefuroxime and ceftriaxone were 91.1% (752/825), 83.0% (685/825) and 78.4% (647/825), respectively, and Escherichia coli was sensitive to piperacillin/tazobactam and meropenem; The resistance rate of Streptococcus pneumoniae to tetracycline was 100% (5 746/5 746), while the resistance rate of Staphylococcus aureus to penicillin was 92% (3 519/3 825), and the resistance rate of MRSA to clindamycin and erythromycinhad were both higher than 90%, and all the above Gram-positive bacteria were sensitive to vancomycin, linezolid, etc.

There were significant differences in the detection rates of pathogens from children with CAP in Zunyi region among different years, seasons and age groups. In 2024, the detection rate of Gram-negative bacteria exceeded that of Gram-positive bacteria. The dominant pathogenic bacteria varied among different age groups, and the infection rates were higher in autumn and winter. Common pathogenic bacteria were highly resistant to various conventional antibiotics. It is necessary to select reasonable antibiotics according to the drug sensitivity test results.