Comparative Evaluation of ELISA and Real-time PCR Tests to Detect COVID-19

Abstract

Background: Considering the wide spread of covid-19 and its high death rate, it is very important to find a sensitive and accurate diagnostic method. Thus, this study compared two main diagnostic approaches; PCR and ELISA, to detect COVID-19. Methods: Fifty patients admitted to Baghiyatalah Hospital were examined to detect COVID-19 RNA by Real-time PCR method, as well as for the presence of IgG and IgM antibodies by ELISA method. The results were statistically analysed by SPSS software. Results: The mean age of patients is 38.4 years old. The percentage of positive cases of COVID-19 in the studied patients according to PCR and ELISA tests was 66% and 70%, respectively. There was a statistically significant difference between positive cases of COVID-19 detected by PCR and ELISA with emerging fever, weakness, and lethargy . The diagnostic value of ELISA versus PCR showed that the sensitivity, specificity, positive likelihood ratio, and true positive rate were 100%, 88.2%, 8.5, and 94.29%, respectively. Conclusion: Although the sensitivity of detection in Real-time PCR is higher than that in ELISA, there is a high agreement between the two methods when used for diagnosis of COVID-19.