Turkeys at a Minnesota poultry farm in 2012 appear in this photo from Bethany Hahn. Midwestern states are struggling to contain a virulent strain of bird flu that has doomed millions of turkeys and chickens since March. (Bethany Hahn via AP)

The outbreak of avian flu that some experts are calling the worst in U.S. history has claimed more than 32 million birds in 16 states. And it’s beginning to take its toll at the grocery store as well.

The cost of a carton of large eggs in the Midwest, where the disease has had the biggest impact, jumped 17 percent in the past month, the Associated Press reported. Meanwhile turkey prices, which were expected to fall this year, have risen between 3 and 10 percent, depending on the cut of meat.

But shoppers are most likely to feel the flu’s effects when buying processed products that include eggs as ingredients, like cake mix and mayonnaise. In Iowa, where most eggs go to these types of products, more than 40 percent of the state’s roughly 60 million egg-laying chickens have been killed by the disease or authorities working to prevent it from spreading.

You'll see higher egg prices at the grocery store, thanks to a bird flu outbreak. PostTV explains the egg shortage, and what products will be more expensive next. (Jhaan Elker, Rebecca Schatz and Julie Percha/The Washington Post)

The price of those eggs has jumped 63 percent in the past 3 weeks, commodity market analyst Rick Brown told the AP.

[Millions of hens to be euthanized at Iowa farm with bird flu]

The rapidly worsening outbreak has killed more birds than any other incidence of avian flu, researchers at the University of Illinois reported last week. First detected among a tiny backyard flock in southern Oregon, it reached the Midwest in early March and has since devastated the region’s poultry industry. Iowa, Minnesota and Wisconsin have all declared states of emergency in response to the outbreak. On Tuesday, the U.S. Department of Agriculture announced that Nebraska had become the 16th state hit by the virus — a flock of 1.7 million chickens is the first to be infected in the state.

According to the USDA, the virus is being spread by wild geese and ducks, which carry the disease without appearing sick. Though two strains of the virus are currently circulating among wild and domestic flocks, the vast majority of deaths have been caused by a strain called H5N2, the USDA reported. This “highly pathogenic” form of the disease can wipe out huge flocks in a matter of days, but poses little risk to humans, according to the Centers for Disease Control. Still, the agency urged people to avoid contact with sick or dead birds and noted the slim chance that the disease could jump into humans.

The number of confirmed cases represents a fraction of the 8.7 billion birds slaughtered in the U.S. each year, the University of Illinois researchers pointed out. Even among the country’s 360 million-bird laying population, which has been hit the hardest, only about 1 in 20 hens has been infected — a significant portion, but not enough to drastically affect the nation’s egg supply.

The outbreak has raised alarms in countries that import U.S. poultry. China, South Korea and Angola — three of the top 10 markets for American poultry — have imposed total bans on imports from the U.S., Reuters reported last month.

But the biggest impact has been on affected farmers, who have had to cull their entire flocks in an effort to prevent the virus from spreading. Once a flock has been destroyed, the farm must be quarantined, scrubbed and disinfected before it can be repopulated with birds, according to the Sioux City Journal.

“The stress level is very high among all my farmers at this point,” Gretta Irwin, executive director of the Iowa Turkey Federation, told the Journal. “Whether you have the virus and have to deal with the emotional grief of losing your flock of turkeys, or if you don’t have the virus and you’re worrying about those who do and what happens next.”