This year’s outbreaks of highly pathogenic avian influenza (HPAI) are hitting egg-laying flocks the hardest, as they did in 2014 and 2015.
Laying hens account for two-thirds of this year’s toll, which more than doubled to 7.65 million birds over the weekend, said the USDA on Monday.
The first outbreak of HPAI in Wisconsin since 2015 was this year’s largest — 3 million laying hens on a farm in Jefferson County, roughly midway between Milwaukee and Madison, the state capital.
Among seven outbreaks reported over the weekend were a flock of 915,925 laying hens in Taylor County, Iowa — near the Missouri border — and a flock of 664,061 hens in Cecil County, Maryland, in the state’s northeastern corner.
Iowa, the No. 1 state for eggs, produces one of every seven eggs nationwide, followed by Indiana, Ohio, Pennsylvania, and Texas.
“High path” bird flu, a contagious viral disease, can quickly wipe out a flock, so agricultural officials ruthlessly cull infected flocks in hopes of preventing the disease from spreading. “Producers are encouraged to move their birds indoors when possible to prevent contact with wild birds and their droppings,” said Wisconsin state officials.
HPAI can be spread by migratory waterfowl and also by contact with infected poultry, contaminated vehicles, and equipment that move between farms and farmworkers’ clothing. Wild birds are seemingly unaffected by HPAI. The virus is not considered a risk to people.
More than 50 million chickens and turkeys died in the 2014-15 epidemic. The losses included 12% of the hens laying eggs for table consumption and 8% of turkeys being raised nationwide, according to a 2017 USDA report. “In response to this historic animal-disease event, many destination markets for US poultry commodities levied trade restrictions on US poultry exports, distorting markets and exacerbating economic losses.”
Nearly 5.1 million laying hens have died from HPAI or in eradication efforts this year, a small part of the 389 million or so laying hens in the country. Nationwide, the hens produced 111 billion eggs, or 285 eggs apiece, in 2021, according to USDA’s Chickens and Eggs annual report.
Besides the three outbreaks in laying flocks, the USDA also confirmed HPAI in 36,000 turkeys on a farm in Charles Mix County, South Dakota, and in backyard flocks in Kansas, Illinois, and Maine over the weekend.
Since the first outbreak was confirmed in US domestic flocks on February 8, the largest losses have been in Wisconsin, followed by Delaware with 1.4 million birds, Maryland with 1.3 million, and Iowa with 965,741 birds. Fifteen states have seen outbreaks.
The USDA list of outbreaks is available here.