How did Iowa's Avian Flu outbreak get this bad?

Aired: 5/2/2015 | 0:03:16 | Clip
Iowa, the country's largest egg-producing state, declared a major outbreak of the Avian Flu. And to try and contain the disease, millions of chickens and turkeys there and in Wisconsin and Minnesota have been killed. Amy Mayer, a reporter for Harvest Public Media at Iowa Public Radio joins Hari Sreenivasan via Skype from Ames, Iowa, to discuss.