Volume 24, Number 7—July 2018
Research
Avian Influenza A Virus Infection among Workers at Live Poultry Markets, China, 2013–2016
Table 1
Seroprevalence of microneutralization titers against influenza A(H7N9), A(H9N2), and A(H5N1) viruses in poultry workers, swine workers, and controls, eastern China, 2013–2016*
Antigen/year |
No. seropositive/no. total (% [95% CI]) | |||
---|---|---|---|---|
Poultry workers |
Swine workers |
Controls |
p value |
|
H7N9 | ||||
2013 | 3/511 (0.58 [0.12–1.71]) | 0/569 (0 [0–0.65]) | 2/915 (0.22 [0.03–0.79]) | 0.13 |
2014 | 3/533 (0.56 [0.12–1.64]) | 1/589 (0.17 [0–0.94]) | 1/881 (0.11 [0–0.63]) | 0.19 |
2015 | 3/535 (0.56 [0.12–1.63]) | 0/501 (0 [0–0.73]) | 0/855 (0 [0–0.43]) | 0.04 |
2016 | 0/491 (0 [0–0.75]) | 1/367 (0.27 [0.01–1.51]) | 1/785 (0.13 [0–0.71]) | 0.48 |
Overall† |
9/964 (0.93 [0.43–1.76]) |
2/1,079 (0.19 [0.02–0.67]) |
4/1,545 (0.26 [0.07–0.66]) |
0.03 |
H9N2 | ||||
2013 | 1/511 (0.20 [0.01–1.09]) | 0/569 (0 [0–0.65]) | 2/915 (0.22 [0.03–0.79]) | 0.61 |
2014 | 2/533 (0.38 [0.05–1.35]) | 1/589 (0.17 [0–0.94]) | 1/881 (0.11 [0–0.63]) | 0.70 |
2015 | 11/535 (2.06 [1.03–3.65]) | 0/501 (0 [0–0.73]) | 4/855 (0.47 [0.13–1.19]) | <0.001 |
2016 | 7/491 (1.43 [0.58–2.92]) | 3/367 (0.82 [0.17–2.37]) | 2/785 (0.25 [0.03–0.92]) | 0.05 |
Overall† |
18/964 (1.87 [1.11–2.94]) |
3/1,079 (0.28 [0.06–0.81]) |
9/1,545 (0.58 [0.27–1.10]) |
<0.001 |
H5N1 | ||||
2013 | 1/511 (0.20 [0–1.09]) | 0/569 (0 [0–0.65]) | 0/915 (0 [0–0.40]) | 0.26 |
2014 | 0/533 (0 [0–0.69]) | 0/589 (0 [0–0.62]) | 0/881 (0 [0–0.42]) | NA |
2015 | 0/535 (0 [0–0.69]) | 0/501 (0 [0–0.73]) | 0/855 (0 [0–0.43]) | NA |
2016 | 17/491 (3.46 [2.03–5.49]) | 0/367 (0 [0–1.00]) | 0/785 (0 [0–0.47]) | <0.001 |
Overall† | 18/964 (1.87 [1.11–2.94]) | 0/1,079 (0 [0–0.34]) | 0/1,545 (0 [0–0.24]) | <0.001 |
*NA, the statistics were not performed because of 0 in the 2 groups.
†The overall seroprevalence was calculated as the number of seropositive persons divided by the number of all new enrolled persons during the study period.
1These authors contributed equally to this article.