Department of Pathogenic Biology.
Department of Respiratory, Children's Hospital of Hebei Province, Shijiazhuang.
Medicine (Baltimore). 2021 Feb 5;100(5):e23786. doi: 10.1097/MD.0000000000023786.
Community acquired-pneumonia (CAP) has varying causative pathogens and clinical characteristics. This study investigated the prevalence of Mycoplasma pneumoniae (M pneumoniae) and evaluated the clinical characteristics in infected hospitalized children by disease severity.From throat swabs of hospitalized children (5 months to 14 years) with CAP collected between November 2017 and May 2018, M pneumoniae and other CAP pathogens were identified using polymerase chain reaction (PCR). Differences in clinical and laboratory test data were compared between severe and mild case groups.Of 333 hospitalized children enrolled, 221/333 (66.4%) tested positive for M pneumoniae and 24/221 (10.9%) patients were (n = 9, aged <5 years vs n = 15, ≥5 years) single infection by PCR, however, only 170/333 (51.1%) patients were presented with M pneumoniae IgM-positive. M pneumoniae detection rate by PCR was higher than by immunoglobulin (IgM) serology. In 123/221 (55.7%) M pneumoniae infected patients, coinfection with bacterial pathogens (n = 61, <5 years vs n = 62, ≥5 years) occurred. Children (aged 3-8 years) had most M pneumoniae infection. Severe M pneumoniae pneumonia (MPP) in children occurred mostly in older age (7 [interquartile ranges {IQR}, 6-8] years; P < .0001), with longer cough days (14 [IQR, 10-19.5] days; P = .002) and hospitalization duration (9.5 [IQR, 7-12.3] days; P < .0001), lower lymphocyte ratio (24.1, [IQR, 20.0-31.1] %; P = .001), higher neutrophils ratio (66.0, [IQR, 60.2-70.3]%; P < .0001), and serum C-reactive protein (CRP) level (3.8, [IQR, 1.3-10.9] mg/L; P = .027).M pneumoniae is the most commonly detected pathogen in CAP. High coinfection prevalence increases diagnosis difficulty by clinically nonspecific characteristics. M pneumoniae detection by PCR with IgM may improve precise and reliable diagnosis of community-acquired MPP.
社区获得性肺炎（CAP）的致病病原体和临床特征各不相同。本研究旨在调查肺炎支原体（M pneumoniae）的流行情况，并通过疾病严重程度评估感染住院患儿的临床特征。
从 2017 年 11 月至 2018 年 5 月采集的 333 例因 CAP 住院的儿童（5 个月至 14 岁）的咽拭子，采用聚合酶链反应（PCR）鉴定 M pneumoniae 和其他 CAP 病原体。比较重症和轻症患儿的临床和实验室检查数据的差异。
在纳入的 333 例住院患儿中，221/333（66.4%）经 PCR 检测 M pneumoniae 呈阳性，24/221（10.9%）患儿为（n=9，年龄<5 岁 vs n=15，≥5 岁）PCR 单感染，但仅有 170/333（51.1%）患儿呈现 M pneumoniae IgM 阳性。PCR 检测 M pneumoniae 的检出率高于免疫球蛋白（IgM）血清学检测。在 221 例 M pneumoniae 感染患儿中，123/221（55.7%）合并细菌病原体感染（n=61，年龄<5 岁 vs n=62，年龄≥5 岁）。3-8 岁儿童最易感染 M pneumoniae。儿童重症 MPP 多发生在较大年龄（7 [四分位距 {IQR}，6-8] 岁；P<0.0001），咳嗽时间更长（14 [IQR，10-19.5] 天；P=0.002），住院时间更长（9.5 [IQR，7-12.3] 天；P<0.0001），淋巴细胞比例更低（24.1%，IQR，20.0-31.1%；P=0.001），中性粒细胞比例更高（66.0%，IQR，60.2-70.3%；P<0.0001），血清 C 反应蛋白（CRP）水平更高（3.8 [IQR，1.3-10.9] mg/L；P=0.027）。
M pneumoniae 是 CAP 最常见的病原体。高合并感染率增加了因临床非特异性特征导致的诊断难度。PCR 结合 IgM 检测 M pneumoniae 可能会提高对社区获得性 MPP 的精确、可靠诊断。
