Validation of S-iELISA
To analysis the specificity and sensitivity of S-iELISA, a total of 111
pig serum samples were tested by IFA (Fig 5A) and S-iELISA,
respectively. As shown in Fig 5B, the IFA detected 92 SADS-CoV-positive
samples, of which 90 tested SADS-CoV-positive by S-iELISA. On the other
hand, of the remaining 19 samples that tested SADS-CoV-seronegative by
IFA, 18 of them were tested SADS-CoV-negative by S-iELISA. Hence, the
sensitivity of S-iELISA was 97.8% among SADS-CoV-seropositive
individuals, and the specificity was 94.7% among SADS-CoV-seronegative
individuals using IFA as standard evaluation method. These results
suggest that the overall coincidence rate of the S-iELISA to IFA was
97.3%.