TABLE 4.
Summary of the serological survey in PRRSV-positive and -negative domestic swine farms by HI assay
| Farm and PRRSV status | No. of sera positivea for B/Yamagata lineageb | Positive (%) | No. of sera positive for B/Victoria lineagec | Positive (%) |
|---|---|---|---|---|
| Positive | ||||
| A | 4/10 (48)d | 40 | 0/10 | 0 |
| B | 0/9 | 0 | 0/9 | 0 |
| C | 0/6 | 0 | 0/6 | 0 |
| D | 29/90 (51) | 32.2 | 48/90 (69) | 53.3 |
| Negative | ||||
| A | 0/7 | 0 | 0/7 | 0 |
| B | 0/9 | 0 | 0/9 | 0 |
| C | 0/9 | 0 | 0/9 | 0 |
| D | 0/90 | 0 | 0/90 | 0 |
a
Data are the number of positive samples out of the total number tested.
b
B/Yamagata/16/1988 was used.
c
B/Brisbane/60/2008 was used.
d
Numbers in parentheses indicate geometric mean HI titers for samples with a value of ≥40.