Analysis: Time to rethink avian flu control strategy
Researcher asks gathering of poultry health professionals from around the world if they think what is collectively being done to control avian influenza is working?
The highly pathogenic avian influenza virus that started the current worldwide epizootic was first isolated from a goose from the Guangdong province of China in 1996. Dr. Carol Cardona, professor, veterinary and biomedical sciences, University of Minnesota, has seen firsthand the devastation that has been caused by the viral descendants of the goose Guangdong influenza virus in Minnesota this year.
She told the audience at the Avian Influenza and poultry trade international conference, in Baltimore, Maryland, that at one point in the outbreak, on April 24, 2015, there were 57 active control zones in Minnesota covering over 7,000 square miles. Every movement involving poultry, eggs, feed or manure in these zones had to be permitted. Every flock in these zones had to be visited and tested. “We can’t do control that way, because the virus will win,” Cardona said.
Killing isn’t working
“The global emphasis has been on the eradication of HPAI (highly pathogenic avian influenza) in gallinaceous birds. Yet the spread continues, and new viruses emerge,” she said. “The central role of the domestic duck populations in the emergence and persistence of the disease has been known for 30 years. We need to control the ducks.”
Because the goose Guangdong virus and the six clades of avian influenza viruses it has spawned have spread from Asia to Europe, Africa and North America, Cardona challenged veterinarians to be open to new ideas and new strategies for eradication. She said, “It is time to rethink biosecurity. It is time to remove surveillance barriers”
Consider vaccine use
“We don’t use vaccines (to control avian flu), because we know it will make things worse,” Cardona said. “For nearly 20 years we have had a pathogen the kills animals, kills humans and has spread across the globe, can it really get worse?”
“We can genome sequence viruses. We now have DIVA (differentiate infected from vaccinated animals) strategies, recombinant vaccines and a larger more sophisticated industry,” she said. “How can we use all of this great new science to move beyond just trying to kill our way out of this?” She stressed that there are multiple pathways that can be taken, there isn’t just one answer.