Table 3.
Incidence rate ratios of diarrhea cases in pigs shedding E. coli with different virulence factors
| Cases/pig days | Incidence rate ratio | 95% Confidence Interval | Std. Err | p value | ||
|---|---|---|---|---|---|---|
| Baseline incidence rate (constant) | 0.06 | 0.03 | 0.11 | 0.02 | 5.5e−22 | |
| Producer | ||||||
| Producer A | 12/415 | 1.00 (base) | ||||
| Producer B | 18/385 | 3.78 | 1.85 | 12.83 | 2.41 | 0.001 |
| Virulence factors | ||||||
| H+, F+T+ | 17/209 | 1.00 (base) | ||||
| H+, F−, T+ | 1/5 | 1.87 | 0.25 | 14.24 | 1.94 | 0.544 |
| H+, F+, T− | 11/150 | 0.25 | 0.09 | 0.68 | 0.13 | 0.007 |
| H+, F−, T− | 2/48 | 0.10 | 0.033 | 0.01 | 0.11 | 0.033 |
| H− | 0/361 | NAa | ||||
Incidence rate ratios were estimated with a Poisson regression model. E. coli was cultured from rectal swabs collected from a cohort of piglets raised at two commercial Danish indoor producers. Data was included from the seventh to the 14th day after insertion to the nursery units
H+/H−, hemolytic E. coli positive/negative; F+/F−, fimbria positive/negative; T+/T−, toxin positive/negative
aIncidence rate was 0