Combination of serological total antibody and RT-PCR test for detection of SARS-COV-2 infections

The purpose of this study was to investigate the feasibility of serological total antibody tests combined with RTPCR for detection of SARS-COV-2. We conducted a retrospective study in which 375 patients were enrolled during the outbreak of SARS-COV-2 from 25th January to 16th March 2020. Patients were divided into a COVID-19 group (n = 141) and a control group (n = 234). Serum samples and throat swabs were collected from 375 patients for total antibody testing against SARS-COV-2 and RT-PCR analysis, respectively. The results indicated that diagnostic sensitivity and specificity were 95.7 % and 98.7 %, 92.2 % and 100 % by total antibody tests and RT-PCR, respectively. The sensitivity and specificity of total antibody tests combined with RT-PCR were 98.6 % and 98.7 %. The sensitivity of the combined method was significantly higher than RT-PCR (X-2 = 5.16, P< 0.05), and similar to that of total antibody tests (X-2 = 1.15, P> 0.05). This study supported the advantage of the combined method for detection of SARS-COV-2 with a high degree of sensitivity and specificity, as a useful tool for accurate diagnosis and timely treatment of suspected patients, epidemiological investigation, as well as monitoring ongoing outbreaks of infections with SARS-COV-2.