Table 2.
Multivariate analysis of the potential risk factors for identifying influenza A (N = 191) and influenza A/H5 (N = 74)in waterfowl in the live-bird markets, Bangladesh, 2007–2012.
| Factors associated with influenza A infection in poultry flocks | Influenza A | Influenza A/H5 | ||||||
|---|---|---|---|---|---|---|---|---|
| Bivariate | Multivariate | Bivariate | Multivariate | |||||
| OR | 95% CI | OR | 95% CI | OR | 95% CI | OR | 95% CI | |
| Influenza A seasonality (Oct–Mar = 1/Apr–Sep = 0) | 1.5 | 1.1–2.0 | 1.5 | 1.1–2.0 | 0.9 | 0.6–1.4 | — | — |
| Poultry flock size (≤20 = 0 vs. >20 = 1) | 1.0 | 0.8–1.4 | — | — | 0.4 | 0.2–0.7 | 0.2 | 0.1–0.5 |
| Dead birds in the week preceding sampling (≤2 = 0 vs. >2 = 1) | 1.4 | 0.7–2.5 | 1.7 | 0.9–3.1 | 0.6 | 0.1–2.3 | — | — |
| Percentages of dead birds in the week preceding sampling (<10% = 0 vs. ≥10% = 1) | 1.5 | 0.8–2.7 | — | — | 0.7 | 0.2–2.7 | — | — |
| Type of bird (ducks = 1 vs. geese = 0) | 5.2 | 2.1–12.7 | 5.3 | 2.2–12.8 | 3.2 | 1.0–10.2 | 2.9 | 0.9–9.3 |
| Age of bird (juvenile = 1 vs. adult = 0) | 0.8 | 0.5–1.2 | — | — | 0.5 | 0.2–1.2 | — | — |
| Health status (apparently healthy = 1 vs. sick = 0) | 2.9 | 0.9–9.1 | 3.4 | 1.1–10.6 | 3.3 | 0.5–23.9 | — | — |
| Type of farming (backyard = 1 vs. small scale = 0) | 0.7 | 0.5–0.9 | 0.7 | 0.5–0.9 | 0.6 | 0.4–0.9 | 0.5 | 0.3–0.9 |
Note: OR – Odds Ratio; CI – Confidence Intervals; Boldface – Statistically significant at <0.05.