Egg farmers in Iowa are reeling from one of the worst avian flu outbreaks in American history. According to the New York Times, since December, the virus has infected over 33 million chickens, turkeys, and ducks. Now, the state has cancelled all upcoming poultry shows in an effort to contain the outbreak and prevent it from spreading to other farms across the country, according to the Iowa Department of Agriculture.

The Center Fresh Group stated recently that it would begin killing and disposing about 5.5 million egg-laying hens. This represents almost 17 percent of the country’s poultry supply that has been deemed unsafe for consumption due to bird flu.

The outbreak appears to have made its way to Midwest farms by way of migratory birds traveling from the Pacific Northwest. Each day, new reports of at least 100,000 infected birds pile up at the Department of Agriculture. Some days, several million birds are reported as infected.

The outbreak has spread as far as South Dakota, where a possible infection of 1.3 million birds was reported on Thursday.

Farmers and local officials are looking for all the help they can get with the gargantuan task of disposing the carcasses. Some desperate farmers have resorted to digging trenches and burying the birds on their own property to avoid the smell and unwanted attention from wildlife. Officials considered employing mobile incinerators or placing the carcasses in local landfills.

One in every five American eggs is laid in Iowa, where more than 40 percent of resident egg-laying hens are now dead or slated to be euthanized. The hens in Iowa are typically packed very densely into stacked cages. This explains why the virus spreads so rapidly across farms, rendering an entire barn’s worth of hens and their eggs unsafe to eat.

While the H1N1 virus, commonly known as bird flu, cannot be contracted by eating fully cooked poultry or eggs, close personal contact with infected birds has resulted in humans becoming infected. There have been no reported cases of interpersonal transmission of H1N1, according to WebMD.

So far, the recent bird flu outbreak has hit 15 states, including Iowa, Indiana, Wisconsin, Arkansas, and California. Iowa is by far the hardest hit, with a reported 24,770,500 cases.

Analysts project that the price of eggs and products containing eggs will rise as a result of the bird flu outbreak.