Table 2.
Multivariate logistic regression model of risk factors associated with the presence of HEV in livers of slaughter-age pigs (n = 90 pig farms, Western France, 2010)
| Variables | % HEV positive* | RR | 95% CI | P value |
|---|---|---|---|---|
| Age gap between first and last slaughter pig shipment to the slaughterhouse for a given batch | ||||
| >20 days | 37·3 | 6·0 | (1·3–66·0) | 0·02 |
| ⩽20 days | 10·0 | – | – | |
| Cross-fostering rate at farrowing | ||||
| >25% | 50·0 | 2·7 | (1·2–5·5) | 0·02 |
| ⩽25% | 23·5 | – | – | |
| Boot-wearing policy | ||||
| Specific to swine production | 11·1 | – | – | 0·01 |
| Non specific | 38·1 | 6·2 | (1·6–45·9) | |
| Origin of drinking water supply | ||||
| >50 m drilling or public network | 19·5 | – | – | 0·047 |
| ⩽50 m (drilling or spring) | 38·8 | 2·9 | (1·2–9·7) | |
| Maternal genetic background | ||||
| Large White × Landrace | 18·2 | – | – | 0·006 |
| Large White × Landrace × Duroc | 55·6 | 2·9 | (1·2–6·7) | |
| Sino-European | 42·9 | 4·5 | (1·6–11·5) |
RR, Relative risk; CI, confidence interval.
*
Percentage of HEV-positive herds/variable category.