Table 2.
Single variate analysis of risk factors
| Variable | Odds Ratio (95%CI) | p |
|---|---|---|
| Farm positive Survey 1 |
1.68 (1.00-2.83) |
0.051 |
| Farm in sampling cluster positive |
2.97 (1.83-4.81) |
<0.001 |
| Season |
|
0.162 |
| Spring |
1.52 (0.71-3.25) |
0.277 |
| Summer |
2.23 (1.08-4.86) |
0.298 |
| Autumn |
1.89 (0.90-3.95) |
0.091 |
| Winter |
- |
- |
| Animal Health Division |
|
0.137 |
| Island |
0.21 (0.07-0.66) |
0.008 |
| Highland |
0.75 (0.35-1.61) |
0.460 |
| North East |
0.63 (0.29-1.35) |
0.231 |
| Central |
0.61 (0.28-1.34) |
0.215 |
| South East |
0.81 (0.43-1.84) |
0.749 |
| South West |
- |
- |
| Management: dairy |
2.23 (1.26-3.96) |
0.006 |
| Management: beef cattle |
0.57 (0.36-0.93) |
0.023 |
| Management: change |
1.93 (0.98-3.80) |
0.058 |
| Pigs present |
2.63 (0.92-7.45) |
0.070 |
| Farm size: large area (>100km2) |
1.57 (0.97-2.56) |
0.069 |
| Farm size: farm area (km2) |
1.93 (1.00-3.61) |
0.040 |
| Total number of cattle |
3.85 (2.04-7.26) |
<0.001 |
| Farms within 1 km |
1.53 (0.90-2.61) |
0.120 |
| Any movementa (open vs closed) |
2.54 (0.98-6.60) |
0.057 |
| Movement within 1 week of sampling |
2.40 (1.24-4.64) |
0.010 |
| Movement within 2 week of sampling |
2.01 (1.10-3.68) |
0.023 |
| Movement within 3 week of sampling |
1.88 (1.07-3.32) |
0.029 |
| Movement within 4 week of sampling |
2.24 (1.33-3.76) |
0.003 |
| Movement within 8 week of sampling |
2.10 (1.29-3.41) |
0.003 |
| No. cattle moved within 4 weeks of sampling |
2.94 (1.38-6.23) |
0.005 |
| No. cattle moved within 8 weeks of sampling |
2.57 (1.41-4.68) |
0.002 |
| Arable agriculturalb |
1.66 (0.90-3.08) |
0.108 |
| Any E. coli non O157 present | 1.73 (1.06-2.80) | 0.027 |
Variables identified from single variate logistic regression models for the presence of E. coli O157 on the 447 Scottish farms that were sampled in both Survey 1 (SEERAD, 1998-2000) and Survey 2 (IPRAVE, 2002-2004).
a Movement (as defined by Cattle Tracing System (CTS) [20]) is deemed to have occurred when an animal is moved on to a specific farm or between herds.
b Arable agriculture (Land Capability for Agriculture class 1-3.1). Prime agricultural land capable for being used to produce a wide range of crops. Favourable climate; slopes are no greater than 7 degrees; soils are at least 45 cm deep; imperfectly drained [21].