The mood at the Western Poultry Conference was sombre as Helen Wojcinski detailed the carnage of the avian influenza outbreak that tore through the U.S. 17 months ago.
More than 10 million turkeys and about 11 per cent of the U.S. layer population lost. More than 220 farms in 15 states hit. Losses of $3 billion during the six-month-long outbreak.
“This was the largest animal disease outbreak in the U.S.,” said Wojcinski, a veterinarian and manager of science and technology with Hybrid Turkeys, an Ontario turkey-breeding company.
“Not just the largest poultry disease outbreak. The largest animal disease outbreak in the U.S. — period.”
The best way to manage avian influenza is to prevent an outbreak before it begins, and that means having robust biosecurity, she said.
There are two types of avian influenza viruses: low path and high path. The former is a milder form, and sometimes easy to miss.
“In some cases, you might not even know that the flock was exposed to it,” said Wojcinski. “If there is mortality with low path, it is often because there is some secondary bacteria, like E coli.”
But low-path viruses that circulate multiple times through flocks can become high path, which causes neurological or respiratory problems and has high mortality rates. That’s what hit American producers, touching down in multiple states simultaneously.
“The industry was prepared for a tornado, but instead we got a tsunami,” said Wojcinski.
Wild waterfowl can harbour the disease and are “flying viral factories,” leaving the virus behind after landing on your water sources or in your fields, she said.
Using surface or pond water as a source of water for poultry can easily bring the virus into the barn.
“If those wild waterfowl land on a source of water, they are excreting the virus into it. The virus can live in the mud at the bottom of the pond for a long period of time.”
People working in fields visited by wild waterfowl can often stir up the virus and can bring it into the poultry barns if they do not clean themselves properly and change their clothing.
“The other thing we always have to be aware of is that the outside of the barn is always dirty and contaminated,” she said.
So any equipment stored outside must be sanitized properly.
But the list of potential threats doesn’t end there.
Wind can spread the virus to a neighbouring farm. Infected but undiagnosed flocks are another threat as the virus can spread as they are transported past other poultry farms. During the avian flu outbreak in the U.S., air sampling found high viral loads inside and immediately outside barns.
“You need to think about where you are parking your cars, and where that vehicle goes afterward,” said Wojcinski. “It becomes a huge biosecurity risk.”
That’s why there should be vehicle wash stations on the farm, and vehicles should be disinfected as they move from one part of the farm to another. Hard surface entry pads is another way to lower the risk.
But the list still goes on. Pest control, proper hand sanitation and clear rules for anyone who works on the farm, including detailed protocols for biosecurity and disinfection. No one who works on a poultry farm should have birds of any kind at home, and employees should only work at one poultry farm.
“This outbreak really caused people to look at their biosecurity thinking,” said Wojcinski. “Most of the time, our biosecurity thinking was to protect the farm and draw the line around your farm. This virus, which was different, was about protecting each barn.”
It was a major effort but the severity of the avian flu crisis means every American farm has been mandated to have their own biosecurity and depopulation plan, she said.
No one wants a repeat.
“In the beginning, it took five to 10 days to depopulate all the birds on a farm,” she said. “As larger layer complexes became infected, it took up to 22 days. So during that period, you had all the birds spewing out the virus, and you had to feed the birds and provide for them. This was a major problem and one of the reasons the outbreak became so extensive.”