The men charged with ridding the farm of a deadly contagion tugged at their dark green protective suits and adjusted the double-intake respirators covering their faces.
"Biosecure. Stop!" read a sign at the farm entrance.
Another sign, in red letters, advised, "All employees & drivers must disinfect tires."
Just past the checkpoint sat Rose Acre Farms, a family-owned egg-laying facility that is one of dozens of poultry farms hit hard by the worst avian influenza outbreak in U.S. history.
The jumpsuits, quarantine zones and bleach for disinfecting are among the tools officials in Iowa, the nation's top egg-producing state, are using to halt...