目的 研究儿童社区获得性肺炎(CAP)病例常见致病微生物在不同性别、年龄、季节的分布及与临床特征的关系。方法 共纳入1 155 例儿童CAP 病例,其中男670 例,女485 例。患儿年龄为1 个月至14 岁,平均年龄为3.1±2.8 岁。采用间接免疫荧光法(IFA)、被动凝集法、酶联免疫吸附试验(ELISA)法、胶体金法和细菌培养法联合检测患儿痰、咽拭子、血标本、肺泡灌洗液和尿中的常见呼吸道致病微生物。结果 病原学检测阳性数为758 例(65.63%);检出率排在前3 位的是肺炎支原体(43.64%)、细菌(15.12%)和呼吸道合胞病毒(9.26%);混合感染率为16.02%。男女患儿的肺炎支原体感染率不同(40.8% vs 47.6%);肺炎支原体在6~14 岁组的检出率最高(77.4%),<1 岁组最低(11.2%),细菌和呼吸道合胞病毒的检出率则以<1 岁组最高(分别为21.2% 和17.2%);夏秋季的肺炎支原体检出率明显高于春冬季,而细菌和呼吸道合胞病毒的检出率则明显低于春冬季(均P<0.05)。肺炎支原体阳性者中出现发热、寒战、咳嗽、湿罗音的比例均高于阴性者;呼吸道合胞病毒阳性者较阴性者更易出现喘鸣音;细菌检测阳性者咳嗽的比例低于阴性者。C 反应蛋白、降钙素原与细菌感染相关(OR 分别为1.747 和1.418,均P<0.05)。结论 肺炎支原体在儿童CAP 致病微生物中占据着越来越重要的地位。要警惕夏秋季节儿童肺炎支原体感染的流行和暴发。不同年龄段CAP 患儿各致病微生物检出率不同。不同致病微生物感染的CAP 患儿的临床特征存在差异。

Objective To study the distribution of pathogenic microorganisms in different genders, age groups and seasons in children with community-acquired pneumonia (CAP) and the relationship between the distribution of pathogenic microorganisms and clinical features. Methods A total of 1 155 children with CAP were enrolled, among whom there were 670 boys and 485 girls, with a mean age of 3.1±2.8 years (range:one month to 14 years). Indirect immunofluorescence assay, particle agglutination test, enzyme-linked immunosorbent assay, colloidal gold method. and bacterial culture were applied to determine common respiratory pathogenic microorganisms in sputum, throat swabs, blood samples, bronchoalveolar lavage fluid, and urine. Results A total of 758 specimens (65.63%) were tested positive by pathogen detection. The top three dominant pathogens were Mycoplasma pneumoniae (MP, 43.64%), bacteria (15.12%), and respiratory syncytial virus (RSV, 9.26%), and the rate of mixed infection was 16.02%. The rates of MP infection between boys and girls with CAP were different (40.8% vs 47.6%;P<0.05). The MP detection rate was the highest in the age group of 6-14 years (77.4%) and the lowest in children younger than 1 year (11.2%), while the detection rates of bacteria and RSV were the highest in children younger than 1 year (21.2% and 17.2%, respectively). The MP detection rate was significantly higher in summer and autumn than in winter and spring, while the detection rates of bacteria and RSV in summer and autumn were significantly lower than those in winter and spring. Among children who were MP positive, fever, chills, cough, crackles were more likely to appear;children with RSV infection were more likely to have wheezes;children with bacterial infection were less likely to have cough. Serum levels of C-reactive protein and procalcitonin were associated with bacterial infection (OR=1.747 and 1.418, respectively;both P<0.05). Conclusions MP plays a more and more important role in the pathogenic microorganisms of CAP in children. Prevalence and outbreaks of MP infection among children should be alerted in summer and autumn. There are differences in the detection rate of various pathogenic microorganisms in CAP children with various age groups. The clinical features of children with CAP caused by different pathogenic microorganisms are different.