新型冠状病毒肺炎病例的血清学检测结果初步分析

目的 了解新型冠状病毒肺炎确诊病例、无症状感染者、密切接触者和其他相关人员血清中IgM和IgG抗体产生情况。 方法 采集研究对象的全血并及时分离血清,采用ELISA和胶体金法对确诊病例和无症状感染者血清进行IgM和IgG抗体检测,采用ELISA对密切接触者和其他相关人员血清进行检测。 结果 用ELISA和胶体金法进行抗体检测,42例确诊病例的阳性情况为:采样日期从第二周起,不论是IgM还是IgG的阳性率均出现增长,第15~35 d组,阳性率最高,IgM抗体阳性率ELISA和胶体金法分别为72.7%与36.4%,IgG抗体阳性率分别为72.7%与90.9%。用ELISA检测,8例无症状感染者为IgM阳性5例(62.5%)和IgG阳性5例(62.5%)。密切接触者为IgM阳性1例(1.7%)和IgG阳性2例(3.4%)。其他相关人员为IgM阳性1例(2.0%)和IgG阳性2例(4.1%)。ELISA IgM、胶体金IgM、ELISA IgG以及胶体金IgG试验检测出阳性确诊病例的发病日期至采样日期的间隔时间中位数分别为16、14、12、13 d。ELISA与胶体金法比对,IgM抗体检测的Kappa值为0.614,IgG的Kappa值为0.716。 结论 新型冠状病毒肺炎确诊病例血清抗体阳性率从第二周起出现显著增长,不同类型人员阳性率差异有统计学意义,ELISA与胶体金法比较中高度一致。

Preliminary analysis on serological test results of cases with coronavirus disease 2019

Objective To study the serum 2019-new coronavirus (2019-nCoV) immunoglobulin M (IgM) andimmunoglobulin G (IgG) antibodies in the confirmed cases of coronavirus disease 2019 (COVID-19), asymptomatic carriers, close contacts and other related personnel. Methods Whole-blood specimens of the surveyed subjects were collected, and the serum was separated in time. Enzyme-linked immunosorbent assay (ELISA) and colloidal gold immunochromatographic assay (GICA) were used to detect IgM and IgG antibodies in the sera of the confirmed cases and asymptomatic carriers, while ELISA was employed to detect IgM and IgG antibodies in the sera of close contacts and other related personnel. Results The positive results of 42 confirmed cases detected by ELISA and GICA were as follows: the positive rates of IgM and IgG both showed an increase from the second week of the sampling, and the positive rates were found to be the highest in the group of the 15^th-35^th days. The positive rates of IgM antibody detected by ELISA and GICA were 72.7% and 36.4%, respectively. The positive rates of IgG antibody detected by ELISA and GICA were 72.7% and 90.9%, respectively. Among 8 asymptomatic carriers detected by ELISA, 5 (62.5%) cases were IgM positive and 5 (62.5%) cases IgG positive. 1 (1.7%) close contact was IgM positive and 2 (3.4%) close contacts IgG positive. As for other related personnel, 1(2.0%) case was IgM positive and 2 (4.1%) cases IgG positive. The median interval from the onset of illness to the sampling date in confirmed cases detected by ELISA for IgM, GICA for IgM, ELISA for IgG and GICA for IgG were 16, 14, 12 and 13 days, respectively. The results detected by ELISA and GICA were compared, and the Kappa values of IgM and IgG antibodies detection were 0.614 and 0.716, respectively. Conclusions The positive rates of serological tests of the confirmed COVID-19 cases presented a significant increase from the second week of the sampling, and the positive rates of different types of people showed statistically significant differences. The consistency of ELISA and GICA for 2019-nCoV IgM and IgG antibodies was medium-high.