Table 2. Characteristics of the study population, Zhejiang, China, 2010-2012.
| Characteristic | Seropositive sample (%) (n=55) | Seronegative sample (%) (n=1,114) | P value | Total sample No. (%) (n=1,169) |
|---|---|---|---|---|
| Age group, years | 0.87 | |||
| 15-30 | 6 (10.9) | 89 (8.0) | 95 (8.1) | |
| 31-46 | 21 (38.2) | 413 (37.1) | 434 (37.1) | |
| 47-62 | 23 (41.8) | 507 (45.5) | 530 (45.3) | |
| 63-78 | 5 (9.1) | 97 (8.7) | 102 (8.7) | |
| 79-95 | 0 (0.0) | 8 (0.7) | 8 (0.7) | |
| Sex | 0.41 | |||
| Male | 33 (60.0) | 605 (54.3) | 638 (54.6) | |
| Female | 22 (40.0) | 509 (45.7) | 531 (45.4) | |
| Source of poultry workers | 0.56 | |||
| Live bird markets | 13 (23.6) | 228 (20.5) | 241 (20.6) | |
| Large scale poultry companies | 25 (45.5) | 512 (46.0) | 537 (45.9) | |
| Poultry slaughtering and processing plants | 0 (0.0) | 36 (3.2) | 36 (3.1) | |
| Household members bred backyard poultry | 17 (30.9) | 338 (30.3) | 355 (30.4) | |
| Had fever | 0.44 | |||
| Yes | 0 (0.0) | 21 (1.9) | 21 (1.8) | |
| No | 38 (69.1) | 805 (72.3) | 843 (72.1) | |
| Missing | 17 (30.9) | 288 (25.9) | 305 (26.1) | |
| Exposure history | ||||
| Direct or close contact with poultry | 52 (94.5) | 832 (74.7) | 884 (75.6) | |
| Direct or close contact with sick or dead poultry | 10 (18.2) | 87 (7.8) | 97 (8.3) |