TABLE 2.

Antigen subtraction results from 18 discrepant sera as tested by the Focus WNV IgM capture ELISA, PanBio WNV IgM capture ELISA, and WNV IgM IFA

Sample no.Focus IgM ELISA index valueaPanBio IgM ELISA index valueaIgM IFA titerb
Without antigen subtractionWith antigen subtractionWithout antigen subtractionWith antigen subtraction
11.640.022.100.22<16
61.221.103.323.02<16
71.470.002.650.36<16
81.130.961.141.02<16
100.960.041.880.08<16
111.361.101.241.08<16
121.170.346.591.85<16
132.280.004.321.82ND
161.060.841.310.97<16
173.131.002.130.00<16
181.620.003.421.65<16
191.350.003.391.62<16
840.920.001.550.42<16
871.000.001.470.52<16
888.780.008.050.0032
891.590.003.960.85<16
901.300.001.450.49<16
911.860.001.741.04<16
  • a See Materials and Methods for calculation of the index value. The cutoff value for the Focus and PanBio IgM capture ELISAs was <0.90.

  • b IFA titers are shown as reciprocal values. The cutoff value for the IgM IFA was <16. ND, not done.