Application of ELISA and colloidal gold method to detection of 2019-nCoV antibodies in serum
LI Fang-cai1, DAI Zhi-hui1, HE Zi-xiang1, HUANG Yi-wei1, WANG Juan1, HE Fang-ling1, ZHOU Shuai-feng1, OU Xin-hua2, LI Guang-bing3, FAN Le-jun4, ZHAN Zhi-fei1
1. Hunan Provincial Center for Disease Control and Prevention, Changsha, Hunan 410005, China; 2. Changsha Municipal Center for Disease Control and Prevention, Changsha, Hunan 410000, China; 3. Shaoyang Municipal Center for Disease Control and Prevention, Shaoyang, Hunan 422000, China; 4. Huaihua Municipal Center for Disease Control and Prevention, Huaihua, Hunan 418000, China
Abstract:Objective To explore the diagnostic value of enzyme-linked immunosorbent assay (ELISA) and colloidal gold method in detecting serum antibodies of 2019 novel coronavirus (2019-nCoV). Methods Eighty-eight confirmed cases of 2019-nCoV in Hunan province were selected as the case group, while 51 cases with negative nucleic acid test served as the control group. Blood samples of the research subjects were collected, and colloidal gold and ELISA methods were used to detect antibodies of the collected samples. The differences in the detection rates of the two methods were compared. The nucleic acid test results were used as the gold standard to evaluate the test efficacy of ELISA and colloidal gold methods. Results The results of this study showed that the positive rates of 2019-nCoV IgM detected by ELISA and colloidal gold method were both 20.97%, while the positive rates of 2019-nCoV IgG detection were 43.55% and 35.48%, respectively. Among the samples with different onset-sampling intervals, there was no statistically significant difference in the detection rates of 2019-nCoV IgM detected by ELISA and colloidal gold method (both P>0.05). When the onset-sampling interval was less than or equal to 7 days, the difference in the 2019-nCoV IgGtest results of the two detection methods was statistically significant (χ2=5.55,P=0.02), and the detection rate of ELISA (26.47%) was higher than that of colloidal gold method (5.71%). A comparison of different onset-sampling intervals showed that the longer the interval, the higher the positive rates of 2019-nCoV IgM and IgG detected not only by ELISA but also by colloidal gold method. With the nucleic acid test results as the gold standard, no statistically significant differences were found in the sensitivity, specificity, positive and negative predictive values between ELISA and colloidal gold method when detecting IgG and IgM. Conclusions The detection efficiency of ELISA is equivalent to that of colloidal gold method, and both have high specificity and limitations in sensitivity. Neither method is recommended for screening, but they can be used as a supplementary diagnostic method for confirmatory diagnosis or to trace the source of clustered epidemics.
李芳彩, 戴志辉, 贺子翔, 黄一伟, 王娟, 何方玲, 周帅锋, 欧新华, 李广兵, 范乐君, 湛志飞. ELISA法与胶体金法在检测新型冠状病毒血清抗体中的应用探讨[J]. 实用预防医学, 2020, 27(7): 780-782.
LI Fang-cai, DAI Zhi-hui, HE Zi-xiang, HUANG Yi-wei, WANG Juan, HE Fang-ling, ZHOU Shuai-feng, OU Xin-hua, LI Guang-bing, FAN Le-jun, ZHAN Zhi-fei. Application of ELISA and colloidal gold method to detection of 2019-nCoV antibodies in serum. , 2020, 27(7): 780-782.