Wang, Xiao-Feng

china fluenza pandemic mainland china density population population density disease firmed county health analysis factor <0.001 mainland fi rst firmed case disease control travel spread incidence epidemic facility transmission firmed cases control school summer vacation people signi prevention virus temperature school beijing variable humidity holiday chinese center information republic airport world health organization china information system ficant h 1n virus highway value 2009 pandemic risk factors figure result number study world person chinese center invasion effect p values province 2009. age groups table vacation duration survival analysis summer signi ficant organization freeway region distribution system railway analyses pattern intersected january association