Table 2.
Summary of the influenza A virus isolation rates in samples with different characteristics
| Characteristics | No of samples | No. (%) H3 positive | Adjusted OR | 95% confidence intervals | p-value |
|---|---|---|---|---|---|
| Length of stay at slaughterhouse | |||||
| < 1 day | 3446 | 33 (1.0) | 1 | Reference | |
| 1–2 days | 2183 | 23 (1.1) | 1.30 | 0.76–2.25 | 0.339 |
| >2 days | 203 | 2 (1.0) | 1.20 | 0.28–5.08 | 0.802 |
| Transport distance † | |||||
| Nearest† | 3863 | 45 (1.2) | 1 | Reference | |
| More distant† | 1519 | 12 (0.8) | 0.77 | 0.39–1.15 | 0.449 |
| Most distant† | 450 | 1 (0.2) | 0.18 | 0.02–1.34 | 0.094 |
| Anti-H3 HAI titer | |||||
| Sero-negative (<1:40) | 4625 | 52 (1.1) | 1 | Reference | |
| Sero-positive (≥1:40) | 1207 | 6 (0.5) | 0.33 | 0.14–0.79 | 0.012 |
| Sero-prevalence of source farms | |||||
| Low (<10%) | 1963 | 16 (0.8) | 1 | Reference | |
| Moderate (10–30%) | 2047 | 16 (0.8) | 1.16 | 0.57–2.34 | 0.682 |
| High (>30%) | 1822 | 26 (1.4) | 2.25 | 1.17–4.32 | 0.015 |
| Total | 5832 | 58 (1.0) | |||
†
Nearest: Guangdong, including Shenzhen and Zhuhai; More distant: Guangxi, Hainan, Hunan, Jiangxi; Most distant: Hubei, Hebei, Henan, Zhejiang.