Table 1.

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

	Odds ratio (90% confidence interval)
	Farm positive in feed and/or faeces (n = 49)	Farm positive in faeces (n = 31)
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)

Reference variables (baseline) in italics. Odds ratios with p < 0.10 in bold. N.a. = not applicable, due to too few observations in one group.