Security rules against the spread of avian influenza are being applied unevenly or not followed at several farms in Iowa, the state hit hardest by the avian influenza epidemic, “potentially increasing the risks that the disease could spread further,” says Reuters. It reports that at half of six poultry farms that a reporter visited, operations did not comply with USDA or state protocols to restrict access to farms, to provide protective gear to workers, and to clean the wheels of vehicles leaving the farm. “It is not known if conditions like those observed by Reuters exist at other infected Iowa farms, or those in 15 other states with commercial or backyard flocks affected by bird flu,” said the wire service.
The epidemic is the worst outbreak of avian influenza ever to hit the United States, killing more than twice as many fowl as the 17 million birds lost in an 1983-84 epidemic in the U.S. Northeast. The USDA’s running tally lists 179 confirmed cases affecting 40.7 million birds, mostly chickens and turkeys on commercial poultry farms. In Iowa, bird flu has affected 25.5 million birds, mostly egg-laying hens, according to a state list that includes farms where initial tests indicate bird flu. The USDA adds cases to its list after a second round of tests.
“Federal agriculture officials are looking everywhere they can think of” to explain how the virus has spread to commercial flocks from the migratory waterfowl that are believed to have brought bird flu into the Midwest, says NBC. A USDA official says the best hope for containing the disease is a virus-killing hot spell. “Our usual control mechanisms for dealing with its spread among commercial poultry – they don’t work as well,” Jack Shere, associate deputy administrator of the Animal and Plant Health Inspection Service, told NBC.
“Let’s be honest. The biosecurity may be good but it may not be complete,” said Shere. Migrating ducks can contaminate ponds and lakes, where the virus can live for up to 130 days. “And once one farm was infected, lateral spread took over,” said NBC. “That’s when the virus gets spread by other means – perhaps other wild birds carrying it on their feet, rodents carrying it on their feet, trucks carrying it on their tires, farm workers or contractors carrying it on their boots.” Tests have found the bird flu virus in the soil near uninfected farms, says Shere. Tests in Europe have suggested the virus can be carried in wind-blown dust.
The Associated Press cites Shere as saying genetic testing has shown the virus has spread from farm to farm and from barn to barn. “Biosecurity efforts, no matter how much they’ve been improved, are not yet good enough,” says the AP. It says the virus can be spread on clothing, shoes and vehicles, or even by the wind.
The news stories are the strongest takes yet on the limitations in the sanitation and animal health rules employed against avian influenza. And they are clearer in describing ways the disease can be spread, including by people. It was a salient moment when Agriculture Secretary Tom Vilsack told Iowa Public Radio on May 15 that the ongoing spread of bird flu could be caused by humans. Before then, the focus was almost exclusively on natural routes of transmission.
The epidemic may force scientists to conduct more research on transmission of influenza. It may also force animal health officials to revise their rules on containing the disease. The fall migration of waterfowl could carry a new threat of avian influenza from flocks that mixed during the summer. So far, the eastern half of the country has been free of bird flu.
Some foodmakers are looking to Europe as the source of eggs for import because U.S. production is being constrained by the epidemic, said Reuters. “Nearly one-quarter of the hens that lay ‘breaker eggs’ – which include liquid, dried or frozen eggs used by food manufacturers – have either died or are slated to be euthanized.” The price for breaker eggs has more than doubled, to $1.83 a dozen, from 63 cents a dozen in late April, and table eggs now sell for an average $2.03 a dozen, compared to $1.19 in late April, said Reuters.
The USDA’s suggested biosecurity checklist is available here.