Photos of bare grocery refrigerator cases and tales of egg prices gone wild have been rampant on social media this winter. The scenes aren’t manufactured drama. The U.S. Department of Agriculture noted last week that some grocery stores have been limiting the number of cartons customers can buy and hanging signs announcing shortages where cartons of eggs would normally be stacked.

Avian influenza (bird flu) is impacting wild birds worldwide and causing outbreaks in U.S. poultry and dairy cows, with human cases mainly reported in dairy and poultry workers. Presumptive positives have been reported in Marshall and Tama counties.