The worst epidemic of avian influenza ever to hit U.S. poultry farms resulted in the death or culling of 48.1 million fowl, most of them turkeys and egg-laying hens. Iowa, the No. 1 egg state, could see “total economic damage” of $957 million, says Fortune. U.S. egg production, estimated down by 5 percent this year, is not expected to recover until 2016.
“But perhaps the most troubling aspect of the crisis is its implications for the viability of industrial-scale farming,” says Fortune. The huge poultry farms, with millions of birds, follow operating rules intended to prevent contamination. “But when a virus pierces such defenses, or when defenses lapse, having all of one’s eggs in one basket (so to speak) can make the impact more devastating.” Disease can quickly spread through thousands or tens of thousands of birds.
In Iowa, the single largest outbreak claimed 5.7 million laying hens on an egg farm in Buena Vista County in the northwestern corner of the state. In all, 22 egg farms lost 24.7 million hens, according to the Iowa Agriculture Department. Total losses in the state, counting turkeys, young chickens and laying hens, were 31.5 million birds.
Experts say migratory birds spread the disease through their droppings. “But it seems to have spread among farms in the Midwest in novel, unforeseen ways. The role of wind and even ventilation systems—transmission routes that current biosecurity strategies don’t address—are now the subject of intense study and anxiety,” says Fortune.
In an initial report on June 15, the USDA said lapses in biosecurity and environmental factors had a role in the epidemic. The department said it observed lapses such as the “sharing of equipment between an infected and noninfected farm; employees moving between infected and noninfected farms; lack of cleaning and disinfection of vehicles moving between farms; and reports of rodents or small wild birds inside the poultry houses.” It said there also were indications the virus was spread by gusty spring winds.
USDA chief scientist John Clifford and the head of the department’s poultry research laboratory will be lead-off witnesses at a Senate Agriculture Committee hearing on Tuesday on the impact of bird flu.
There have been no confirmed cases of bird flu in two weeks, says the USDA