2015-05-17 00:00:00 EAGLE GROVE, IA - MAY 17: No trespassing signs are posted on the edge of a field at a farm operated by Daybreak Foods which has been designated "bio security area" on May 17, 2015 near Eagle Grove, Iowa. Daybreak Foods is one of several large-scale commercial poultry facilities is Iowa reported to have been hit with a highly pathogenic strain of avian influenza which has forced poultry producers to kill off millions of birds in an attempt to stifle the spread of the illness. A road leading up to the front of the farm has been closed to outside traffic with a checkpoint established. Scott Olson/Getty Images/AFP == FOR NEWSPAPERS, INTERNET, TELCOS & TELEVISION USE ONLY == PluimveeNieuws

Hoogpathogene vogelgriep in Verenigde Staten