OSAGE COUNTY, Mo. – The U.S. Department of Agriculture reports that highly pathogenic avian influenza has been confirmed in a turkey flock in Osage County, Missouri. Samples were sent for testing after a sudden increase in deaths in the flock.

The Missouri Department of Agriculture officials have quarantined the area and culled the Missouri flock. They say these birds did not enter the food supply.

Better known as bird flu, avian influenza is a family of highly contagious viruses that are not typically harmful to most wild birds that transmit it, but are deadly to domesticated birds. The Associated Press reports that the virus spreads quickly through poultry flocks and almost always causes severe disease or death, so when it is detected, officials quarantine the site and cull all the birds in the infected flock.

As of early November, this outbreak had led to the culling of over 50 million birds from Maine to Oregon, driving up prices for eggs and poultry – including holiday turkeys. This matches the toll from a 2014-2015 bird flu outbreak that previously was considered the most significant animal disease event in U.S. history.

Illinois state wildlife officials suspect that bird flu killed at least 300 waterfowl found dead in November at public hunting sites across southern Illinois. The Illinois Department of Natural Resources said the wild birds, mostly snow geese, have been found dead at Baldwin Lake, Pyramid State Recreation Area, Rend Lake and Carlyle Lake. The state agency is asking anyone who sees 20 or more dead birds at one spot to report those birds deaths to a district wildlife biologist.