Table 2 Exposure History of Influenza A(H7N9) Case-Patients During the First (March 31-September 30, 2013), Second (October 1, 2013 – September 30, 2014) and Third (October 1, 2014 – September 30, 2015) Waves of H7N9 Virus Circulation
Exposure | Wave 1(N = 127) | Wave 2(N = 296) | Wave 3(N = 207) |
|---|---|---|---|
Exposure to poultry | 26 (20.5) | 56 (19.0) | 50 (24.2) |
Exposure to live bird markets (LPM) | 84 (66.1) | 203 (68.6) | 136 (65.7) |
Working at a LPM | 15 (17.9) | 40 (19.7) | 12 (8.8) |
Visiting of LPMs | 69 (82.1) | 163 (80.3) | 124 (91.2) |
No exposure to poultry | 13 (10.2) | 27 (9.1) | 16 (7.7) |
Possible limited H-H transmission | 4 (3.1) | 7 (2.3) | 4 (1.9) |
Both possible limited H-H transmission and common exposure to poultry | - | 3 (1.0) | 1 (0.5) |