©2008 Association of Schools of Public Health SYNOPSIS

Understanding interactions between animals and humans is critical in prevent-ing outbreaks of zoonotic disease. This is particularly important for avian influenza. Food animal production has been transformed since the 1918 influenza pandemic. Poultry and swine production have changed from small-scale methods to industrial-scale operations. There is substantial evidence of pathogen movement between and among these industrial facilities, release to the external environment, and exposure to farm workers, which challenges the assumption that modern poultry production is more biosecure and biocon-tained as compared with backyard or small holder operations in preventing introduction and release of pathogens. An analysis of data from the Thai gov-ernment investigation in 2004 indicates that the odds of H5N1 outbreaks and infections were significantly higher in large-scale commercial poultry operations as compared with backyard flocks. These data suggest that successful strate-gies to prevent or mitigate the emergence of pandemic avian influenza mus