DES MOINES – Questions are still flying since Monday’s announcement of a second case of avian influenza in Iowa, this time at a northwest Iowa egg farm.
The roughly four million laying hens at that site will be euthanized to control the spread of the disease, and state and industry officials are still unsure of the economic impact of eradicating six percent of Iowa’s layer population.
Also unclear is how exactly the current strain of H5N2 avian influenza is transmitted. Wild migratory birds are believed to be the root of the problem, which is believed to be one reason Minnesota, with its lakes, has seen so many cases. Addressing reporters in a teleconference yesterday, USDA’s Chief Veterinary Officer Dr. John Clifford said authorities are still working on it.
”We’re trying to determine the possible pathway of introduction into these houses,” Clifford explained, “but my guess is; and right now there’s no solid evidence of such, but my guess it that it’s probably multiple pathways of entry. And that doesn’t mean people are using poor biosecurity. In fact, the biosecurity we’ve had in place has been very beneficial in protecting us from high-pathogenic avian influenza, but this is different than what we’ve normally been addressing.”
That’s because standard biosecurity protocol addresses disease spread from one farm to the next. Clifford said producers should now incorporate environmental factors into their disease control measures.
Authorities are also monitoring migratory flight paths or flyways much as they did in the mid- to late 2000s. At that time, Clifford said officials had concerns about human health risks if the lethal H5N1 bird flu virus arrived in the United States from Asia.
“It’s been quite a few years after that,” said Cifford. “So we still do surveillance in the flyways, but not at that level. We’ve requested addiitonal resources to increase our sampling of the flyways themselves.”
Clifford said proper funding means authorities could ramp up monitoring efforts by the next migration season. He also told reports he expects additional cases to occur this fall and next spring as wild birds follow migratory patterns.
The current strain of H5N2 avian influenza is not a known threat to human health.
To hear more about the current understanding of avian influenza in Iowa, click the audio player above this story.