Table 4 Differences in farm characteristics between A(H1N1)pdm09v-positive and enzootic IAV-S-positive farmsa
From: Effect of herd size on subclinical infection of swine in Vietnam with influenza A viruses
Variable | A(H1N1)pdm09v-positive farms, no. (%) | Enzootic IAV-S-positive farms, no. (%) | P value* | |
|---|---|---|---|---|
Total number of pigs | <50 | 4 (50.0 %) | 0 (0.0 %) | |
50 to 500 | 0 (0.0 %) | 1 (6.7 %) | ||
500 to 1000 | 0 (0.0 %) | 1 (6.7 %) | ||
>1000 | 4 (50.0 %) | 13 (86.7 %) | 0.01 | |
Other animals on farm | No | 0 (0.0 %) | 9 (60.0 %) | |
Yes | 8 (100.0 %) | 5 (33.3 %) | ||
No answer | 0 (0.0 %) | 1(6.7 %) | 0.01 | |
Farm type | Family-operated farm | 4 (50.0 %) | 2 (13.3 %) | |
Corporate farm | 4 (50.0 %) | 13 (86.7 %) | 0.13 | |
Shower-in facility for humans | No | 3 (37.5 %) | 2 (13.3 %) | |
Yes | 5 (62.5 %) | 10 (66.7 %) | ||
No answer | 0 (0.0 %) | 3 (20.0 %) | 0.24 | |
Disinfection facility for vehicles | No | 3 (37.5 %) | 4 (26.7 %) | |
Yes | 5 (62.5 %) | 11 (73.3 %) | 0.66 | |
Type of operation | Not farrow-to-finish | 3 (37.5 %) | 2 (13.3 %) | |
Including farrow-to-finish | 5 (62.5 %) | 13 (86.7 %) | 0.30 | |
Type of pig house | Open-sided or semi-open-sided house | 8 (100.0 %) | 13 (86.7 %) | |
Windowless | 0 (0.0 %) | 2 (13.3 %) | 0.53 | |
Introduction of pigs from external source | No | 0 (0.0 %) | 1 (6.7 %) | |
Yes | 7 (87.5 %) | 11 (73.3 %) | ||
No information | 1 (12.5 %) | 3 (20.0 %) | 1.00 | |
Vaccination | No | 0 (0.0 %) | 1 (6.7 %) | |
Yes | 5 (62.5 %) | 14 (93.3 %) | ||
No answer | 3 (37.5 %) | 0 (0.0 %) | 0.03 |