The Nebraska Department of Agriculture says about 1.8 million additional chickens must be killed to stop the spread of the U.S.'s largest bird flu outbreak in seven years.

On Saturday, Nebraska health officials released a statement confirming the state's 13th case of bird flu this year. Avian influenza is a highly contagious virus, spreading easily among birds. Human contraction is rare, as long as poultry and eggs are sufficiently cooked.

The latest discovery of bird flu happened on a farm in northeast Nebraska. Nebraska has already seen 6.8 million birds infected with the virus this year, placing only behind neighboring Iowa for the state with the most infections. In 2022 alone, Iowa has had to cull more than 15 million birds.

This year, more than 50 million birds have died as a result of the flu outbreak. Most have been killed — incinerated or buried, but some have perished from the virus itself.

In the past, bird flu tended to die out during the summer heat, but this year is different. The flu steadily spread during the summer, making a resurgence in September, when more than 6 million chickens were killed nationwide to slow the spread.

Bird flu can survive for weeks in contaminated environments, leading to the mass killings of birds when an infection is detected. This year's outbreak contributed to the rise in chicken and egg prices throughout the country, along with breeding and supply chain issues.

Prices have just recently begun to return to normal levels, as demand eases during the winter months.

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