According to the USDA Animal and Plant Health Inspection Service, 12 new outbreaks of high-path avian flu were confirmed on 22 April, affecting at least 482,350 birds. The number of birds affected is still pending for one of these outbreaks.

All the birds affected were turkeys in Minnesota; 11 of the outbreaks were in commercial flocks and one in a backyard flock.

It appears that 10 of these outbreaks were already reported the previous day and there are just two new outbreaks on the APHIS list, both in Minnesota:

• Pipestone county:150 backyard turkeys, and
• Kandiyohi county: 62,600 commercial turkeys.

All these were in the area of the Mississippi flyway for migrating wild birds and were caused by the H5N2 variant of the virus.

Other bird flu outbreaks reported

• Wisconsin: The avian flu virus has been detected at a second commercial turkey facility in Barron County in a flock of 90,000 birds, according to Wisconsin Department of Agriculture, Trade and Consumer Protection.
• Wisconsin: Another flock has been quarantined, making six cases of bird flu in Wisconsin and more than one million chickens affected, reports Fox News.
• Iowa: The Iowa Department of Agriculture and Land Stewardship has announced an outbreak of highly pathogenic avian influenza (HPAI) in a commercial turkey flock in Sac County. The facility has 34,000 turkeys and is within the 10 kilometer monitoring zone surrounding the initial HPAI case in Buena Vista County. This is the third case of HPAI in Iowa.

State of emergency in Wisconsin, Minnesota

In response to the avian influenza, state Governor Mark Dayton has issued an Emergency Order, declaring a peacetime state of emergency on 23 April.

On 20 April, Wisconsin Governor Scott Walker signed an Executive Order, authorising the Wisconsin National Guard to assist authorities in the response to the avian influenza virus affecting Jefferson, Juneau and Barron counties.

Overview of high-path avian flu outbreaks in US poultry

The following information is based in published USDA APHIS outbreak reports.

• The latest cases bring the total number of high-path avian flu outbreaks since December 2014 to 73.
• Outbreaks have occurred in poultry in 13 states.
• Three of the early outbreaks were caused by the H5N8 sub-type of the virus but in all those since mid-February 2015, the H5N2 variant has been confirmed.
• The majority of outbreaks have been in commercial turkeys (58); three have been in commercial chickens and 12 in backyard flocks.
• The number of poultry affected by these outbreaks has reached almost 7.4 million, according to our calculation. This figure includes over 4.1 million commercial chickens, 3.3 million commercial turkeys and over 7,000 backyard poultry.
• USDA APHIS puts the total number of poultry affected at 7,358,523.
• The disease has also affected five captive wild birds.