A strain of highly pathogenic avian influenza, or bird flu, is spreading across wild and commercial bird flocks in the US.
This week, the USDA confirmed the presence of highly pathogenic avian influenza (HPAI) in two non-commercial backyard flocks (less than 50 birds) in Connecticut and western Iowa. While it’s possible for the virus to spread to humans, no human cases have been reported.
The detection of the bird flu in Iowa is especially concerning, considering the state is home to the largest number of egg-laying hens in the US. The 2015 outbreak of the same pathogen resulted in the death and eradication of 50 million birds across 15 states, with 33 million hens killed in Iowa alone, costing the federal government nearly $1 billion. But because the Iowa flock in question was small and non-commercial, there aren’t yet any supply chain issues in the region, says the USDA.
New confirmed cases continue to pop up across the nation. The USDA reported the most recent confirmation of the pathogen in a flock of broiler chickens in Missouri today.
This recent avian flu outbreak stretches across the country, with the first confirmed case detected in Indiana on Feb. 9. Indiana’s outbreak, which started in commercial turkeys, resulted in the killing and removal of 171,000 birds. The spread continued to Kentucky, where 284,000 birds were killed. Delaware had to destroy 1.2 million birds after an infection was detected in a commercial chicken flock.
The USDA reports that the cases of HPAI confirmed in Indiana are the first signs of the strain in commercial poultry in the US since 2020. However, a subtype of the HPAI virus known as H5N1, which was responsible for crushing the poultry industry in 2015, was detected in wild birds in North and South Carolina in late January of this year.
Recent avian flu cases in small, backyard flocks like the one in Iowa have also been found in states including Michigan, Maine, New York and Virginia.
According to the department, the Animal and Plant Health Inspection Service (APHIS) is working closely with state officials to depopulate properties with infected birds—which will not enter the food system—to mitigate the spread. Officials are suggesting poultry farmers immediately report sick birds and tighten their biosecurity measures by limiting the contact of wild and commercial animals.
Despite the large number of cases detected across the nation, the USDA says there is no “immediate public health concern” and, according to the U.S. Centers for Disease Control and Prevention, no human cases have been reported yet.