Why Avian Flu Is in the Air Again
With two different viruses found among U.S. flocks, here's how to keep your family healthy
If you have chickens or other birds in the backyard — keep the veterinarian’s number handy.
A strain of low pathogenic H5N2 avian flu has been discovered in a flock of 84,000 turkeys in Barron County, Wisconsin, according to the U.S. Department of Agriculture (USDA).
It is the second case of avian flu reported in the U.S. in less than a week. A highly pathogenic strain of the H7 bird flu was detected last week in a chicken breeder flock in Tennessee. The birds are being culled in an effort to contain the outbreak. The farm is a contractor for U.S. food giant Tyson Foods Inc.
"The 'highly pathogenic avian influenza' (HPAIV) strain is genetically linked to strains circulating in wild North American birds, so we know it is circulating here and could pop up again even if the Tennessee outbreak is fully contained," said Dr. Meghan May, an associate professor of microbiology and infectious diseases at the University of New England College of Medicine.
"Anyone who has backyard chicken flocks should be watching for an increase in sick birds. A vet should be called in immediately," said one infectious disease expert.
Chances are, large-scale farms have been keeping a close eye on global outbreaks — so the latest developments are no surprise. "Watching for additional poultry outbreaks would give us an idea of how prevalent it is," she told LifeZette. "On an individual level, anyone who has backyard chicken flocks should be watching for an increase in sick birds. A vet should be called in immediately, and contact with sick chickens should be avoided."
The HPAIV strain H7N9 is rampant in Chinese poultry right now, said May. She added that what has started to circulate here seems to be a relative of the strain circulating in China — but it's not likely to have come directly from there.
"While H7N9 [the Chinese variant] can cause disease in humans with a terrifyingly high mortality rate, it does not yet have the ability to spread from person to person," said May. "Thus far, people only contract [illness] directly from poultry. This is why it is critical for anyone with backyard flocks exhibiting HPAIV symptoms to immediately call a vet and avoid contact. We do not yet know how the TN strain affects people, but if it is reminiscent of H7N9, that would be a very bad thing."
These initial cases of bird flu in the U.S. have prompted several Asian countries to limit imports of U.S. poultry. They are the first detected here since a widespread outbreak in 2014 and 2015, during which nearly 50 million birds, mostly egg-laying hens, were euthanized. The losses pushed U.S. egg prices to record highs, and some large-scale farms are only now fully recovering from the outbreak.
May said the USDA has responded quickly to these initial cases in an effort to contain the viruses, and it's an excellent example of some of the less visible work the department does on a regular basis. "Often the management of these crises goes by without much thought so long as everything works out well. It seems a good moment to point out who is doing this very critical work."