Abstract：Objective To analyze the detection results of respiratory and blood samples from 82 confirmed cases of COVID-19 in Changde City, to find more characteristics and epidemic rules of severe acute respiratory syndrome coronavirus2(SARS-CoV-2), and to provide a basis for formulating scientific and highly effective prevention and control strategies. Methods We collected respiratory and blood specimens from 82 confirmed cases of COVID-19 in Changde City from January 24 to February 22, 2020 according to the requirements of the Prevention and Control Plan of Novel Coronavirus Pneumonia (the 5th Edition) issued by National Health Commission, and then performed SARS-CoV-2 and influenza virus nucleic acid tests, blood routine test and antibody test. The test results of different specimens and methods were compared, and statistical analysis was performed. Results Among specimens from the 82 confirmed cases, the positive rate of nucleic acid test for SARS-CoV-2 in respiratory specimens was 93.9%, and the influenza virus A/B nucleic acids were both negative. Among the specimens positive for SARS-CoV-2, the Ct values of most specimens were distributed in a higher interval. The viral load of SARS-Cov-2 was low, and no statistically significant difference was found in the Ct value between severe and ordinary cases (P>0.05). The positive rates of SARS-CoV-2 specific IgM and IgG antibodies in blood specimens were 64.6% and 78.0%, respectively, and the positive rate ofblood specimens was significantly lower than that of nucleic acid detection (χ2=24.059,P＜0.001). C-reactive protein was generally high in blood specimens, the total number of white blood cells and the total number of lymphocytes were normal or low, and there were statistically significant differences in white blood cells and lymphocytes between male and female groups (χ2=7.165, χ2=3.998, both P<0.05). All results of nucleic acid test for SARS-CoV-2 in blood specimens showed negative. Conclusion The SARS-CoV-2 viral load of respiratory specimens from the confirmed cases of COVID-19 in the early stage is not high, and hence, it is easy to miss. No statistically significant difference is found in the viral load between severe and ordinary cases. The combined use of nucleic acid detection of respiratory specimens, antibody detection of blood specimens and routine blood analysis can complement each other, and plays an important role in effective prevention and control of the epidemic and observation of therapeutic efficacy of the cases.
2021, Vol. 28 
