H5N1 bird flu activity is spiking at poultry farms across the U.S., with 1.32 million birds affected over the past month, according to the latest federal data .

Illinois’s Clinton County has seen the biggest outbreak of highly contagious virus, with 934,600 chickens reported sick.

There are also large outbreaks in Minnesota, Wisconsin and North Dakota. A turkey farm in Minnesota’s Roseau County has seen 57,000 birds affected, another in North Dakota has had 60,600 birds fall ill and one in Wisconsin has seen 41,400 infections, the Department of Agriculture’s tracker shows.

Past outbreaks at egg-laying farms have resulted in major surge in egg prices for Americans after sick birds were killed. Bird flu has also led to the deaths of farm workers and people exposed to sick animals.

Bird flu has sickened more than 1.3 million birds over the past month across the US, as well as cattle and mink.…