After the devastating bird flu epidemic in the Midwest earlier this year, the disease has not been seen in the country since Utah wildlife officials found an infected mallard at Farmington Bay on Great Salt Lake on July 31. State and federal officials are testing thousands of wild birds each month to identify hot spots for the virus as an “early warning” to producers. Wild waterfowl are believed to spread the disease through their droppings while migrating.
So far, fears of a new outbreak during the fall migration have not been realized. Poultry industry and USDA officials say it’s still early to draw conclusions about the risks this season. The fall migration generally begins in late September and runs through November. Warm weather may have delayed the movement southward.
“While we are glad we haven’t seen any positive cases yet, we’re certainly not relaxing our safeguards and preparations for a possible recurrence this winter and spring,” said a USDA spokeswoman. Poultry farms have tightened biosecurity measures to reduce the chance of wild animals or farm workers carrying the virus into barns that may hold thousands of birds. The National Chicken Council, representing the broiler industry, said growers have made biosecurity a top priority. “I am confident we are in a much better place,” said NCC spokesman Tom Super.
“Unfortunately, high path avian influenza will not be a one- or two-year challenge, though,” said Super. “The virus is a global threat, so heightened biosecurity will have to be the ongoing norm.”
It’s nearly a year since the disease, called highly pathogenic avian influenza because it can kill a flock in two days, was confirmed in two wild ducks in Washington State in early December 2014, marking the beginning of the latest outbreak. The worst came last spring, with nearly 90 percent of the commercial flock casualties coming in April and May in the upper Midwest.
Almost 50 million chickens and turkeys were lost in the epidemic, including 10 percent of hens that lay eggs for table consumption. Iowa, the No. 1 egg state, and Minnesota, the leader in turkey production, were hit the hardest. The federal government spent more than $950 million in eradicating outbreaks and compensating owners for dead flocks.
At the close of last week, the USDA requested bids from drug makers to produce at least 100 million doses per month of bird flu vaccine, and storage space for up to 500 million doses. The vaccine would be used to treat chickens and turkeys ranging in age from a day old to 3 years. “Nationally, the placement rate of laying hens and meat turkeys is approximately 20 million birds per month. With each bird requiring two doses of vaccine prior to placement, 80 million doses per month will be needed just for these two sectors alone,” said the USDA in setting the monthly requirement of 100 million doses.
The agency stressed it has not approved any use of vaccines but it wants to stockpile it to be ready “should be decision be made to use it.” The USDA’s animal health agency, which awarded two contracts in August for vaccine, said it would make requests quarterly through September 2016 for effective vaccines.
When bird flu is detected, the USDA’s usual approach is to quarantine the area around the infected farm and destroy the flock as a way to prevent the virus from multiplying and spreading. The goal against bird flu is to kill flocks within 24 hours of diagnosis. The agency says “standard methods … are preferred” in depopulation, such as carbon dioxide gas and a thick foam sprayed over birds. On a case by case basis, “the use of ventilation shut-down for depopulation” may be used, it said. Some animal welfare groups say the ventilation shutdown is unduly cruel.