Table 2. Serologic results for animal samples tested in different serologic assays, the Netherlands*.
| Animal | Cohort | SARS-CoV-2 S1 ELISA† | SARS-CoV-2 RBD ELISA† | VNT‡ | No. samples | Result |
|---|---|---|---|---|---|---|
| Cat |
SARS-CoV-2 exposed, n = 44 | + | + | + | 10 | Seropositive |
| – | – | – | 34 | Seronegative | ||
| 2020, n = 500 |
+ | + | + | 2 | Seropositive | |
| + | + | – | 4 | Suspected | ||
| – | + | – | 6 | Seronegative | ||
| – |
– |
–/NA |
488 |
Seronegative |
||
| Dog | SARS-CoV-2 exposed, n = 1 | + | + | + | 1 | Seropositive |
| 2020, n = 500 | + | + | + | 1 | Seropositive | |
| + | – | – | 8 | Seronegative | ||
| – | – | –/NA | 491 | Seronegative |
*NA, not applicable; RBD, receptor-binding domain; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; S1, spike protein subunit 1; VNT, virus neutralization titer; –, negative; +, positive. †An ELISA optical density value greater than or equal to the cutoff value of 0.4 is a positive result, and an ELISA OD value less than the cutoff value is a negative result. ‡Neutralization titers of samples were determined by using the reciprocal of the highest dilution that resulted in >50% reduction of luciferase activity in pseudovirus virus neutralization. A VNT greater than or equal to the cutoff value of 16 is a positive result, and a VNT less than the cutoff value is a negative result.