Table 3 Summary of exposure variables associated with PRRSV status in the univariable analysis (p≤0.2)
Variable name | Value | Number of PRRSV positive (%) | Number of PRRSV negative (%) | OR | 95% CI | P-value |
|---|---|---|---|---|---|---|
Herd size | <250 | 14 (31.1) | 38 (48.1) | 1.0 | Â | Â |
(Number of sows) | ≥250 | 31(68.9) | 41(51.9) | 2.0 | 0.9-4.4 | 0.06 |
Farm type | outdoor | 8 (17.8) | 29 (34.5) | 1.0 | Â | Â |
| Â | indoor | 37 (82.2) | 55 (65.5) | 2.4 | 1.0-5.9 | 0.05 |
PRRS vaccine | none | 16 (34.8) | 68 (80.0) | 1.0 | Â | Â |
| Â | killed | 2 (4.3) | 6 (7.1) | 1.4 | 0.2-7.6 | Â |
| Â | live | 28 (60.9) | 11 (12.9) | 10.8 | 4.4-26.2 | <0.01 |
APP ELISA | negative | 7 (15.2) | 29 (34.1) | 1.0 | Â | Â |
| Â | positive | 39 (84.8) | 56 (65.9) | 2.9 | 1.1-7.2 | 0.02 |
Avian-like H1N1 | negative | 31 (68.9) | 74 (87.1) | 1.0 | Â | Â |
| Â | positive | 14 (31.1) | 11 (12.9) | 3.0 | 1.2-7.4 | 0.01 |
Age at weaning in days | 21-27 | 30 (65.2) | 33 (40.7) | 1.0 | Â | Â |
|  | ≥28 | 16 (34.8) | 48 (59.3) | 0.3 | 0.1-0.7 | <0.01 |
Disposal of dead pigs | incineration | 6 (13.0) | 33 (42.9) | 1.0 | Â | Â |
| Â | collection | 40 (87.0) | 44 (57.1) | 5.0 | 1.8-13.1 | <0.01 |
Frequency of live | never | 14 (31.1) | 22 (28.2) | 1.0 | Â | Â |
animals | 1-6/year | 11 (24.4) | 45 (57.7) | 0.3 | 0.1-0.9 | Â |
| Â | >6/year | 20 (44.5) | 11 (14.1) | 2.8 | 1.0-7.7 | <0.01 |
Pig density* | <15000 | 20 (43.5) | 68 (81.0) | 1.0 | Â | Â |
|  | ≥15000 | 26 (56.5) | 16 (19.0) | 5.5 | 2.4-12.2 | <0.01 |
Other production species | no | 34 (73.9) | 44 (53.0) | 1.0 | Â | Â |
| Â | yes | 12 (26.1) | 39 (47.0) | 0.4 | 0.1-0.8 | 0.02 |
Number of farm | 1-2 | 5 (10.8) | 28 (35.0) | 1.0 | Â | Â |
workers | 3 | 16 (34.8) | 20 (25.0) | 4.4 | 1.4-14.2 | Â |
| Â | 4 | 14 (30.4) | 12 (15.0) | 6.5 | 1.9-22.2 | Â |
| Â | >4 | 11 (23.9) | 20 (25.0) | 3.1 | 0.9-10.2 | 0.01 |
Use of straw yards | no | 16 (38.1) | 43 (53.1) | 1.0 | Â | Â |
| Â | yes | 26 (61.9) | 38 (46.9) | 1.8 | 0.8-3.9 | 0.11 |
Ventilation weaners | natural | 22 (47.8) | 54 (64.3) | 1.0 | Â | Â |
| Â | artificial | 14 (30.4) | 20 (23.8) | 1.7 | 0.7-3.9 | Â |
| Â | both | 10 (21.7) | 10 (11.9) | 2.4 | 0.9-6.7 | 0.15 |
Ventilation growers | natural | 26 (56.5) | 61 (73.5) | 1.0 | Â | Â |
| Â | artificial | 7 (15.2) | 9 (10.8) | 1.8 | 0.6-5.4 | Â |
| Â | both | 13 (28.3) | 13 (15.7) | 2.3 | 0.9-5.7 | 0.13 |
Ventilation finishers | natural | 22 (51.1) | 60 (72.3) | 1.0 | Â | Â |
| Â | artificial | 14 (32.6) | 12 (14.5) | 3.1 | 1.2-7.9 | Â |
| Â | both | 7 (16.3) | 11 (13.2) | 1.7 | 0.6-5.0 | 0.04 |
Ventilation lactating | natural | 16 (34.8) | 43 (51.8) | 1.0 | Â | Â |
sows | artificial | 21 (45.6) | 28 (33.7) | 2.0 | 0.9-4.5 | Â |
| Â | both | 9 (19.6) | 12 (14.5) | 2.0 | 0.7-5.6 | 0.17 |
Lighting weaners | natural | 15 (32.6) | 41 (48.8) | 1.0 | Â | Â |
| Â | artificial | 13 (28.3) | 17 (20.2) | 2.1 | 0.8-5.3 | Â |
| Â | both | 18 (39.1) | 26 (31.0) | 1.9 | 0.8-4.4 | 0.19 |
Lighting lactating | natural | 9 (19.6) | 30 (36.1) | 1.0 | Â | Â |
sows | artificial | 21 (45.6) | 22 (26.5) | 3.2 | 1.2-8.3 | Â |
| Â | both | 16 (34.8) | 31 (37.4) | 1.7 | 0.6-4.5 | 0.04 |
Presence of cattle | no | 40 (87.0) | 64 (77.1) | 1.0 | Â | Â |
| Â | yes | 6 (13.0) | 19 (22.9) | 0.5 | 0.2-1.3 | 0.18 |
Presence of poultry | no | 41 (89.1) | 64 (77.1) | 1.0 | Â | Â |
| Â | yes | 5 (10.9) | 19 (22.9) | 0.4 | 0.1-1.1 | 0.10 |
Large white in breed | 0 | 2 (4.4) | 13 (16.3) | 1.0 | Â | Â |
composition in % | 1-25 | 36 (80.0) | 55 (68.7) | 4.2 | 0.9-19.9 | Â |
| Â | >25 | 7 (15.6) | 12 (15.0) | 3.8 | 0.6-21.9 | 0.11 |