2020年江苏省306例不同特征新冠肺炎病例咽拭子病毒载量分布

Distribution of throat swab viral load of 306 covid-19 cases with different characteristics in Jiangsu Province in 2020

目的分析不同临床严重程度的新型冠状病毒(SARS-CoV-2)病例咽拭子中的病毒载量,及与患者年龄、性别和发病间隔的关系,为深入了解SARS-CoV-2的传染性和致病性提供依据。方法采用实时荧光定量反转录聚合酶链式反应(RT-qPCR),对2020年江苏省306例入院前未经抗病毒治疗的新冠肺炎(COVID-19)病例咽拭子中SARS-CoV-2病毒载量进行检测,并对不同病情患者的病毒载量进行分析。结果306例新冠肺炎病例中,男性占56.9%,30~59岁占68.0%;普通肺炎型占66.7%,轻症无肺炎型占24.8%,重症肺炎型占8.5%;病例发病和首次SARS-CoV-2核酸阳性的发病间隔为-4~15 d,主要集中在0~8 d(256例,占83.7%)。不同年龄组病情分布差异有统计学意义(P<0.01):轻症以2~29岁组占比高(36.2%),普通肺炎型以30~59岁组占比高(70.2%),重症肺炎型以60~97岁组占比高(21.6%);不同年龄组重症占比、不同发病间隔组病情分布差异均有统计学意义(P值均<0.01)。普通肺炎组、重症肺炎组和轻症非肺炎组病例平均病毒载量对数值分别为(5.93±1.23)、(6.17±1.54)、(6.28±1.28)/ml(log10),差异无统计学意义(t=1.02,P=0.31);部分患者尤其是轻症患者发病时已检出新冠病毒核酸阳性且病毒载量较高(6.43±1.34)/ml(log10);重症肺炎患者的平均病毒载量在发病间隔4~5 d组最高,非重症肺炎患者在发病间隔2~3 d组最高。结论不同特征新冠肺炎病例病毒载量分布存在一定差异;病毒RNA载量与病情有一定关系。

Objective To analyze the viral load in throat swabs of patients with different clinical severity of novel coronavirus(SARS-CoV-2)and its relationship with age,gender and interval of onset;to provide basis for further understanding the infectivity and pathogenicity of SARS-CoV-2.Methods Real-time fluorescence quantitative reverse transcription PCR was used to detect the viral load in the throat swab of 306 COVID-19 patients in 2020 before taking antiviral therapy,and the viral load levels of patients in different conditions were analyzed.Results Among the 306 COVID-19 cases,56.9%were male,and 68.0%were 30 to 59 years old,66.7%were with common pneumonia,24.8%were mild without pneumonia,and 8.5%were suffered with severe pneumonia.The onset interval of nucleic acid positive was-4 to 15 d,mainly between 0 to 8 d(256 cases,accounted for 83.66%).There was a statistically significant difference in the distribution of disease condition among different age groups(P<0.01):the highest proportions were observed in the 2-29-year old group(36.2%)among the mild disease type patients,in the the 30-59-year old group(70.2%)among the common pneumonia type patients and the 60-97-year old group(21.6%)among the severe pneumonia type.The logarithm values of the average viral load in the common pneumonia group,severe pneumonia group and mild non-pneumonia group were(5.93±1.23),(6.17±1.54),(6.28±1.28)/ml(log10),respectively,and the difference was not statistically significant(t=1.02,P=0.308);some patients,especially those with mild symptoms,had been detected positive for SARS-CoV-2 nucleic acid and had a high viral load level(6.430±1.115)/ml(log10)before onset;the highest average viral load of patients with severe pneumonia and non-severe pneumonia patients were observed in the onset interval of 4 to 5 d and 2 to 3 d,respectively.Conclusion SARS-CoV-2 viral load was related with the clinical characteristics of COVID-19 patient,the disease condition was correlated with viral RNA load.