评价宏基因组二代测序（mNGS）技术在社区获得性肺炎（CAP）病原体检测中的应用价值。

回顾性分析2021年2月至8月于浙江大学医学院附属第一医院临床诊断为CAP并行mNGS检测及实验室常规方法检查的345例住院患者的临床资料。记录每位患者的人口学特征、mNGS检测与实验室常规方法检查的结果、抗感染方案和调整方案前后C反应蛋白（CRP）及降钙素原（PCT）水平。

实验室常规方法检测为阳性的患者有173例，发现33种微生物；mNGS检测为阳性患者共315例，发现130种微生物。mNGS检测阳性率较实验室常规方法显著提高[91.30%（315/345）vs. 50.14%（173/345），χ² = 129.097，P < 0.001]，一致性检验Kappa = 0.105，P = 0.001。且在抗生素暴露的294例患者中，mNGS阳性率显著高于实验室常规方法[90.48%（266/294）vs. 49.32%（145/294），χ² = 109.924，P < 0.001]。同时，mNGS与实验室常规方法确诊率的比较，差异具有统计学意义[85.22%（294/345）vs. 39.13%（135/345），χ² = 141.040，P < 0.001]。与入院时比较，调整抗感染方案后3 d，基于mNGS检测结果作为病原学诊断依据的患者CRP[68（24，118）mg/L vs. 12（5，46）mg/L，Z = 6.154，P < 0.001]及PCT[0.53（0.20，0.93）μg/L vs. 0.25（0.08，0.54）μg/L，Z = 2.572，P = 0.010]水平均显著降低。

在CAP患者病原学的检测中，mNGS技术具有既往抗生素暴露的影响少、检测病原体广泛等优点，可以作为一种可行的补充手段。

To evaluate the clinical application value of metagenomic next-generation sequencing (mNGS) technology in the diagnosis of community-acquired pneumonia (CAP) pathogens.

A total of 345 inpatients who were clinically diagnosed with CAP and examined by mNGS and laboratory routine methods in the First Affiliated Hospital, Zhejiang University School of Medicine from February to August 2021 were retrospectively analyzed, and their clinical data were collected. The demographic characteristics, the results of mNGS and laboratory routine tests, the anti-infection regimen, and the levels of C-reactive protein (CRP) and procalcitonin (PCT) before and after regimen adjustment were recorded.

There were 173 positive patients tested by laboratory routine methods with 33 microorganisms, and 315 positive patients by mNGS with 130 microorganisms. The positive rate of mNGS was much higher than that of laboratory routine methods [91.30% (315/345) vs. 50.14% (173/345), χ² = 129.097, P < 0.001], with the consistency test Kappa = 0.105, P = 0.001. The positive rate of mNGS in the 294 patients exposed to antibiotics was also significantly higher than that of laboratory routine methods [90.48% (266/294) vs. 49.32% (145/294), χ² = 109.924, P < 0.001]. Meanwhile, there was a statistically significant difference in the diagnosis rate between mNGS and laboratory routine methods [85.22% (294/345) vs. 39.13% (135/345), χ² = 141.040, P < 0.001]. Compared with at admission, the levels of CRP [68 (24, 118) mg/L vs. 12 (5, 46) mg/L, Z = 6.154, P < 0.001] and PCT [0.53 (0.20, 0.93) μg/L vs. 0.25 (0.08, 0.54) μg/L, Z = 2.572, P = 0.010] in the patients with mNGS results as the basis for etiological diagnosis decreased markedly on the third day after adjusting the anti-infection regimen.

In the etiological detection of CAP patients, the mNGS technology has the advantages of less impact of previous antibiotic exposure and broader detection of pathogens, which can be a feasible supplementary means.