The association between H5N1 outbreaks and influential factors by logistic regression analysis.

*ORs of the variables involving minimal distances to the nearest water bodies, wetlands, transportation routes, bird migration routes and main cities were calculated for a ten-kilometer difference, ORs were estimated regarding annual precipitation for a 100-millimeter difference, elevation for a 100-meter difference and poultry density for 1000-bird difference per square kilometer.