(NDAgConnection.com) – About 1.8 million more chickens must be killed in Nebraska to prevent the spread of a highly pathogenic bird flu virus, state officials said, as the U.S. sees its worst outbreak of the disease in seven years. The state’s latest spate of bird flu was found on an egg-laying farm in northeast Nebraska’s Dixon County, the Nebraska Department of Agriculture said Saturday.

As the virus sweeps through commercial and backyard chicken and turkey flocks, agriculture officials are encouraging poultry producers to look out for signs of infection and report any cases to state or federal officials, reports Farms.com.

Nebraska, where 6.8 million birds have been affected by the outbreak, is the second worst-hit state behind Iowa, where 15.5 million birds have been culled.

This year, more than 50 million birds in 46 states have already died — mostly from being slaughtered to control the spread, but some from the deadly virus itself. It’s the largest outbreak since 2015, when 50 million birds died.

There’s little chance of humans contracting the virus. Human cases are extremely rare, according to the Centers for Disease Control and Prevention, as properly cooking poultry and eggs will kill bacteria and viruses.

The bird flu outbreak has also contributed to the rise in consumer prices for eggs and poultry meat, on top of hiked-up costs from inflation.