The US is facing the largest bird flu outbreak ever. This adds to the rising cost of food and is a reminder that the health of wildlife, pets and animals and people are closely intertwined. Scientists call this interconnection “one health.”
Of particular note this week is the fact that avian influenza, or “bird flu,” is driving up the cost of Thanksgiving turkeys. My forbes.com colleague and fellow scientist, Bruce Y. Lee, reported three days ago that Thanksgiving turkeys are still up about 20% from last year, and that’s less than the 73% peak a few months ago, less partly because retailers opted to absorb the difference.
Where does bird flu come from?
Bird flu is not new. In fact, wild birds are the primary reservoir of most flu viruses. In the past century, new human flu viruses have emerged on four separate occasions — in 1918, 1957, 1966, and 2009 — when avian flu viruses were “established” in humans again.
because novel human Since flu viruses are relatively rare, one might think that bird flu itself is rare. But this is not the case. Bird flu affects a wide variety of wild bird species, from ducks and geese to gulls and waders.
One study found that the prevalence of influenza antibodies – a measure of previous infections – in laughing gulls (leucophagus atricilla) is between 25%-72%. In some places, the prevalence of flu in wild birds is known to be as high as 50%.
Most of these influenzas are known as low pathogenic avian influenza (LPAI). Unlike highly pathogenic avian influenza (HPAI), LPAI rarely causes symptomatic illness. While LPAI is almost always present, HPAI is prone to more episodic and dramatic outbreaks.
Like LPAI, HPAI viruses are carried by wild birds. But, unlike LPAI, when HPAI enters poultry, it quickly spreads from bird to bird, causing outbreaks that can be devastating to commercial flocks.
Outbreak of highly pathogenic bird flu
North America is currently in the midst of its largest outbreak of HPAI since 2014-2015, when approximately 7 million turkeys and 43 million chickens were lost to disease or “overpopulation,” a USDA policy and control strategy that requires all birds. be killed. The 2014-2015 outbreak cost taxpayers an estimated $879 million in government spending, a figure that does not include uncompensated costs to producers, making the 2014-2015 HPAI outbreak the costliest animal health incident in U.S. history is.
Now the current outbreak is poised to surpass these numbers. According to the CDC, as of November 22, 2022, a total of 50,461,200 birds were affected — roughly equal to the 2014-2015 total. Although the outbreak is slowing down (the peak seems to have been in September and October), new infected herds are being discovered almost every day.
Counties reporting bird flu range from Florida to Washington and from California to Maine in the US. Only the states of Alabama, Hawaii, Louisiana and West Virginia have not reported infections. Places where infected birds have been found include backyards, petting zoos, game bird production facilities, and farms of commercial breeders of turkeys, ducks, and chickens.
Only one human case has been reported to date. This was in a man who treated birds that were believed to be infected at the time. While the CDC deems the risk to the general public to be low, government officials are urging people who raise chickens in their backyards to use gloves and a face mask or respirator when handling birds after handling the birds. Take precautions such as hand washing and avoidance. Direct contact with clothing or other materials that may be contaminated with animal saliva, mucus, feces.
One health approach to flu
All this is a reminder that human and animal health are intertwined. Zoonoses are animal pathogens that are transmitted to humans and there is evidence that the frequency of zoonoses is increasing. In 2020, the United Nations Environment Program released a report warning that unless action is taken to reduce the spread of pathogens from animals to humans, more events like the COVID-19 pandemic can be expected. Kan This is the idea of One Health, which I have written about before. Our human population and the other species we share this planet with are closely linked. Our fortunes rise and fall together. The high price of holiday turkeys at the moment is a reminder of that.