Development and evaluation of a competitive enzyme-linked immunosorbent assay using a monoclonal antibody for diagnosis of severe fever with thrombocytopenia syndrome virus in bovine sera

Lee, Hyojin; Kim, Eun-Ju; Song, Jae-Young; Choi, Jeong Soo; Lee, Ji Youn; Cho, In-Soo; Shin, Yeun-Kyung

A total of 416 bovine serum samples and two positive control sera were tested with the IFA to distinguish negative serum samples from SFTSV. The results showed that 97.4% (407/418) of the bovine serum samples were negative, while 2.6% (11/418) of the bovine serum samples were positive according to the IFA. cELISA was performed using the SFTS-negative group samples, and the mean inhibition percent was 11.3% with a standard deviation of 12.7%. Therefore, we determined the cut-off value to be 49.5% (mean ± 3SD) (Fig. 5) . The cELISA and IFA were compared using this cut-off value, and 98.1% (410/418) consistency was observed between results ( Table 1 ). The accuracy of cELISA was demonstrated with a plot of the distribution of PI values obtained from the IFA-negative or positive cattle group (Fig. 6) .