Table 4. Risk factors for seroprevalence of antibodies to avian influenza virus A (H5N1) among poultry workers, as determined by logistic regression model analysis, Zhejiang, China, 2010-2012.

Variables	Wald χ2	P	OR	95% CI
Number of poultry bred >1,000	10.993	0.001	3.774	(1.721, 8.726)
Direct or close contact with poultry	6.946	0.008	5.203	(1.526, 17.736)