Table 2.

Odds ratios (OR) from multivariate analysis of potential risk factors for farms being infected with Salmonella Cubana in the outbreak in pig farms in Sweden 2003.

		OR (90% CI
		Farm positive in feed and/or faeces (n = 49)	Farm positive in faeces (n = 31)
Type of production:
Integrated vs piglet		3.19 (0.29 – 35.0)	N.i.
Fattening vs piglet		38.2 (1.57 – 927.8)	N.i.
Herd size:
No. of pigs (OR per extra 100 pigs)
	piglet producing	1.17 (0.90 – 1.52)	N.i.
	fattening	0.84 (0.57 – 1.52)	N.i.
	integrated	1.05 (0.80–1.79)	N.i.
1–5 stable units vs ≥ 11		N.i.	0.22 (0.06 – 0.75)
6–10 stable units vs ≥ 11		N.i.	0.31 (0.08 – 1.23)
Type of feed:
Other feed types vs soy		0.08 (0.01 – 0.75)	N.i.
First feed delivery week:
18 vs 22–23		N.i.	0.27 (0.04 – 1.98)
19 vs 22–23		N.i.	0.22 (0.05 – 0.89)
20 vs 22–23		N.i.	0.33 (0.07 – 1.50)
21 vs 22–23		N.i.	0.15 (0.02 – 1.15)

Reference variables (baseline) are written in italics. N.i. = not included, (not significant in the univariate analysis).