Poultry farmers across the globe remain under threat from an unusually long and lethal bird flu outbreak that has led to the loss of nearly 53 million birds in the US and at least 50 million in Europe. The outbreaks involve a Eurasian H5N1 strain that experts say is behaving differently than anything they’ve seen in the past. Most concerning is that, for the first time, the virus is spreading widely among wild birds and threatening to become a year-round threat, which could have major implications for some poultry production methods.
The current H5N1 strain was first detected in US poultry in February, and has since spread to 46 states so far. According to the US Geological Survey’s National Wildlife Health Center (NWHC), the spatial pattern of the 2022 outbreak clearly shows infections were introduced along both the Mississippi and Atlantic flight corridors of wild birds. This differs from the last major US bird flu outbreak in 2015, which primarily affected Midwestern poultry operations along the Mississippi flyway. Bird flu has since been detected in all four North American flyways and infected at least 100 wild bird species, a new record.
Unlike previous outbreaks, the virus didn’t die off this summer with the arrival of warmer weather. It is also able to infect waterfowl species without causing significant harm, which scientists say allows the virus to be spread even further. The virus is often transmitted when migratory birds defecate mid-flight, which can land directly on farms or travel there later via vehicle tires, worker boots, etc. In the current outbreak, waterbirds are thought to have carried the virus to Canada from Europe and then down the eastern seaboard, according to the NWHC.
Scientists are now warning that the global avian flu outbreak could deepen further as wild bird flocks in North America migrate to Central and South America, which are home to the most diverse bird populations on the planet. Wintering flocks are also expected to be larger due to widespread drought conditions across the Americas. That means a higher number of birds in close proximity to one another, increasing the chances of spreading the disease. Scientists are worried that when some of these birds return to North America in the spring, they will bring with them another wave of bird flu, perpetuating a constant cycle of infections.
For some insight as to what all this might mean for US poultry producers, Bryan Richards, emerging disease coordinator at NWHC, says we might look to Europe. Across the European continent, H5N1 has become a fixture in wild birds, leading to bigger and bigger outbreaks over the past 3 years. Researchers say the virus is also now entrenched in some parts of the US.
Based on HPAI seasonal pattern, the number of outbreaks is expected to continue rising in the coming months and the World Organization for Animal Health (WOAH) recommends that countries maintain their surveillance efforts and biosecurity measures at the farm level. In the UK and most EU countries, those measures include mandates to bring flocks inside. The US Department of Agriculture (USDA) recommends producers bring their birds indoors to prevent exposure but it is not mandatory.
In Europe, the indoor housing orders also apply to poultry and eggs labeled “free-range”, which is a rather loose term suggesting animals are able to roam freely outdoors. In the US, producers can make the claim as long as the birds are given access to an outdoor area, though there is no requirement as to how often the birds need to actually be outside. Europe has slightly more stringent regulations but the indoor housing rules are the same for both free-range and traditional poultry operations.
The big question is what this means for free-range products if indoor housing mandates become a permanent fixture. It is a vexing question, especially when you consider that consumers pay a premium price for these products. British and EU marketing standards allow for free-range laying hens to be kept inside for up to 16 weeks before companies must issue advisories to customers.
In the UK, where a majority of chicken eggs are free-range, producers were required to change egg carton labels from “free-range” to “barn-eggs” when mandatory housing measures kept poultry indoors past the 16-week limit earlier this year. Big free-range producers in the US have not provided a lot of specifics as to how they are handling biosecurity at their facilities, though some have acknowledged that they are prohibiting outdoor access. US authorities do not require producers to update labels when unexpected events like bird flu force a change in production practices. (Sources: Nature, Science, National Geographic, The Guardian)
