Table 1 Odds ratios for possible risk factors for detecting Salmonella Cubana on farms in the outbreak in pig farms in Sweden 2003.

Type of production:

Integrated vs piglet

3.14 (1.09 – 9.02)

1.78 (0.61 – 5.15)

Fattening vs piglet

3.38 (1.11 – 10.28)

1.25 (0.41 – 3.83)

Herd size:

No. of pigs (OR per extra 100 pigs)

1.05 (1.00 – 1.10)

1.03 (1.00 – 1.06)

No. of stable units:

1–5 stable units vs ≥ 11

0.21 (0.05 – 0.85)

0.26 (0.08 – 0.83)

6–10 stable units vs ≥ 11

0.28 (0.06 – 1.29)

0.39 (0.11 – 1.42)

Herd size (divided on type of production):

Piglet producing

big vs small (<500 pigs)

17.50 (1.88 – 163.22)

9.33 (1.08 – 81.0)

Fattening

big vs small (<950 pigs)

0.33 (0.07 – 1.57)

0.30 (0.08 – 1.21)

Integrated

big vs small (<1250 pigs)

1.56 (0.46 – 5.34)

1.76 (0.54 – 5.74)

Type of feed:

soy vs other types

18.32 (3.20 – 104.90)

1.62 (0.68 – 3.85)

Feeding system:

dry vs wet (H2O)

0.92 (0.34 – 2.51)

0.60 (0.21 – 1.69)

wet (whey) vs wet (H2O)

2.50 (0.94 – 6.62)

0.93 (0.37 – 2.33)

wet (whey) vs dry

2.73 (1.02 – 7.29)

1.56 (0.60 – 4.07)

Feed delivery week:

(farms with only one delivery, n = 46)

18 vs 23

0.08 (0.01 – 1.22)

N.a.

19 vs 23

0.50 (0.06 – 4.03)

0.06 (0.01 – 0.45)

20 vs 23

0.21 (0.03 – 1.69)

0.08 (0.01 – 0.70)

21 vs 23

0.28 (0.03 – 2.37)

0.06 (0.01 – 0.52)

22 vs 23

0.22 (0.03 – 1.96)

0.13 (0.01 – 1.10)

No. of feed deliveries:

one vs three or more

1.13 (0.31 – 4.15)

0.35 (0.10 – 1.29)

two vs three or more

0.80 (0.20 – 3.25)

0.45 (0.11 – 1.83)

Amount of feed: (OR per extra ton)

1.04 (1.00 – 1.08)

1.02 (0.99 – 1.04)