TABLE 2.
Correlation between ELISA and seroneutralization results
| Antigen or kita | ELISA resultb | No. of serum samples (%) with seroneutralization resultc
|
|
|---|---|---|---|
| Positive | Negative | ||
| VPX | Positive | 254 (100) | 13 (43.3) |
| Negative | 0 (0) | 17 (56.6) | |
| IDEXX | Positive | 254 (100) | 16 (53.3) |
| Negative | 0 (0) | 14 (46.6) | |
| KPL | Positive | 254 (100) | 22 (73.3) |
| Negative | 0 (0) | 8 (26.6) | |
| VP3 | Positive | 244 (96) | 22 (73.3) |
| Negative | 10 (4) | 8 (26.6) | |
a
Sera were diluted 1/500 for the IDEXX kit or 1/100 for the KPL kit (manufacturers' recommended dilution) and 1/500 for the VPX- and VP3-based ELISAs.
b
For the IDEXX and KPL kits, a serum was considered positive or negative for IBDV according to manufacturers' calculations. For VPX- and VP3-based ELISAs, a serum was considered positive if its OD value was above the cutoff level (0.25).
c
A serum was positive for neutralization if its titer was >50. The percentage was calculated as the number of sera positive or negative relative to the total of sera positive or negative for neutralization, respectively.