Table 2.
Odds ratios for associations between environmental specimens and H7N9 virus contamination, Zhejiang province, China, March 2013–April 2015
| Characteristic | Univariate analysis | Multiple analysis | ||||
|---|---|---|---|---|---|---|
| cOR | 95% CI | P value | aOR | 95% CI | P value | |
| Area type (ref. urban) | ||||||
| Rural | 0·93 | 0·81–1·07 | 0·31 | 0·94 | 0·79–1·11 | 0·45 |
| Premises type (ref. other premises) | ||||||
| Live poultry markets | 8·18 | 6·43–10·41 | <0·001 | 6·92 | 5·33–8·99 | <0·001 |
| Prefecture (ref. Hangzhou) | <0·001 | <0·001 | ||||
| Huzhou | 1·50 | 1·21–1·86 | <0·001 | 1·21 | 0·93–1·59 | 0·16 |
| Jiaxing | 0·36 | 0·28–0·46 | <0·001 | 0·40 | 0·30–0·53 | <0·001 |
| Jinhua | 0·62 | 0·50–0·78 | <0·001 | 0·51 | 0·39–0·66 | <0·001 |
| Lishui, Quzhou, Taizhou | 0·25 | 0·19–0·31 | <0·001 | 0·14 | 0·11–0·18 | <0·001 |
| Ningbo, Shaoxing, Wenzhou, Zhoushan | 0·04 | 0·03–0·06 | <0·001 | 0·04 | 0·03–0·07 | <0·001 |
| Year (ref. 2013) | <0·001 | <0·001 | ||||
| 2014 | 3·47 | 2·42–5 | <0·001 | 3·62 | 2·49–5·26 | <0·001 |
| 2015 | 9·77 | 6·82–14·01 | <0·001 | 10·38 | 7·11–15·15 | <0·001 |
| Sample type (ref. poultry faeces) | <0·001 | <0·001 | ||||
| Poultry cage swab | 1·35 | 1·13–1·62 | <0·001 | 1·47 | 1·19–1·82 | <0·001 |
| Drinking water for poultry | 0·92 | 0·71–1·2 | 0·53 | 1·51 | 1·11–2·05 | 0·01 |
| Sewage from cleaning poultry | 1·90 | 1·52–2·38 | <0·001 | 2·12 | 1·64–2·74 | <0·001 |
| Swabs of tables for slaughtering or holding poultry | 2·17 | 1·80–2·62 | <0·001 | 1·69 | 1·36–2·10 | <0·001 |
| Others | 1·35 | 1·02–1·77 | 0·03 | 2·68 | 1·96–3·68 | <0·001 |
| H9 subtype (ref. negative) | ||||||
| Positive | 7·18 | 6·23–8·27 | <0·001 | 4·49 | 3·79–5·31 | <0·001 |
cOR, Crude odds ratio; aOR, adjusted odds ratio; CI, confidence interval.