Table 3.
Comparison of sensitivity of the in-house Schmallenberg virus ELISA (A) and a commercial SBV ELISA (B) versus virus neutralization test (VNT)
| Dilution of sera | Sera number | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 611 | 612 | 615 | 616 | |||||||||
| VNT | A | B | VNT | A | B | VNT | A | B | VNT | A | B | |
| 1:1 | 1:32 | 98 | 96 | 1:64 | 76 | 189 | 1:64 | 95 | 120 | 1:64 | 81 | 64 |
| 1:4 | 1:16 | 34 | 53 | 1:16 | 34 | 213 | 1:32 | 49 | 102 | 1:16 | 36 | 25 |
| 1:8 | 1:8 | 18 | 34 | 1:8 | 22 | 132 | 1:16 | 31 | 61 | 1:8 | 24 | 21 |
| 1:16 | 1:4 | 9 | 17 | 1:4 | 15 | 86 | 1:4 | 16 | 35 | <1:4 | 11 | 11 |
| 1:32 | <1:4 | 3 | 8 | <1:4 | 8 | 43 | <1:4 | 7 | 16 | 1:4 | 6 | −4 |
| 1:64 | <1:4 | 3 | 4 | <1:4 | 4 | 23 | <1:4 | 5 | 9 | <1:4 | 3 | 11 |
Four out of the positive sera from France (see Table 1); serially diluted 1:4 to 1:64 in negative serum were analyzed in accordance with the protocol of each test. The sera and sera dilutions where further diluted 1:100 in ELISA A, 1:10 in ELISA B and serially diluted 1:4 to 1:256 in VNT. Bold-figures indicate positive results, under-lined figures doubtful results. Thresholds: VNT titer ≥1:8 = positive. ELISA A; S/P% ≥15 = positive, ELISA B; S/P ≥50-60 = doubtful, >60 = positive.