A further four HPAI outbreaks were added to the official count from the USDA Animal and Plant Health Inspection Service (APHIS) on 13 May:

• South Dakota, Yankton county - 70,600 commercial turkeys
• South Dakota, Hutchinson county - 70,000 commercial turkeys
• Iowa, Cherokee county - 45,000 commercial turkeys
• Iowa, Buena Vista county - commercial turkeys (number of birds pending).

In all these outbreaks, the cause has been confirmed as the H5N2 subtype of highly pathogenic avian influenza virus of mixed Eurasian and American origin.

The South Dakota outbreaks are linked to the Central flyway for migrating birds, while the Mississippi flyway covers the Iowa cases.

Second outbreak in Nebraska prompts State of Emergency

On 14 May, the Nebraska Department of Agriculture (NDA) confirmed the presence of a second case of H5N2 HPAI in a commercial layer flock in Dixon County. The second farm (referred to as Dixon 2) is in close proximity to the initial farm (referred to as Dixon 1) identified on 12 May. Both farms are owned and operated by the same producer. Dixon 2 is a flock of 1.8 million chickens.

NDA Director Greg Ibach, said: “Having a second farm in Nebraska confirmed to have HPAI is unfortunate but not completely unexpected. This follows the pattern we’ve seen in other states when it comes to the spread of the virus. NDA will continue to use all the resources at our disposal, in coordination with our federal and state agency counterparts, to manage a quick and effective response.”

Mr Ibach added that both farms are under quarantine, and the birds on both properties will be depopulated. NDA is working with Nebraska Department of Environmental Quality to ensure proper disposal of dead birds. A perimeter has been established around Dixon 2, and as is the USDA protocol, NDA will be visiting all locations within a 6.2-mile radius of the farm that have poultry to conduct testing. Due to the proximity of Dixon 2 to Dixon 1, the 6.2-mile radius overlaps significantly.

Governor Pete Ricketts has issued a state emergency declaration to provide NDA and other state agencies with appropriate resources to address the HPAI situation.

Two new outbreaks suspected in Iowa

On 12 May, Iowa Department of Agriculture and Land Stewardship (IDALS) reported two probable cases of HPAI in Sioux and Plymouth counties.

• Sioux county 12 - pullet farm (number of birds pending)
• Plymouth county 1 - pullet farm (number pending)

Both of these farms experienced increased mortality and initial testing showed they were positive for H5 avian influenza. Additional confirmatory testing is pending from the APHIS National Veterinary Services Laboratories (NVSL) in Ames.

With these new announcements, Iowa now has 52 cases of the disease in the state.

The Department has quarantined the premises and once the presence of the disease is confirmed, all birds on the property will be humanely euthanised to prevent the spread of the disease.

South Dakota records new outbreak

According to South Dakota Animal Industry Board, there has been a further outbreak of HPAI in the state:

• Moody county - commercial egg layers

This latest outbreak – not yet listed by APHIS – was detected on 13 May and brings the total number in the state so far to nine, affecting 1,650,900 birds.

Two new outbreaks in Minnesota

The Minnesota Board of Animal Health has announced two new presumptive virus-positive flocks in the state:

• Renville county 2 - layer chickens (number of birds pending)
• Meeker county 9 - commercial turkeys (number pending)

These brings the state totals to more than 5.76 million poultry affected on 87 farms in 21 counties.

HSUS: "Avian influenza is just one marker of sickness in industrial animal agriculture"

In his latest blog, President and CEO of the Humane Society of the United States (HSUS) writes of the current HPAI situation: "For me, it’s yet another example of how our industrial system of food production is broken. We need more farms and more extensive systems, so the animals raised in agricultural settings are not so vulnerable because they are concentrated on just a few sites."

No new outbreaks in Wisconsin

Wisconsin Department of Agriculture, Trade and Consumer Protection reported no new cases of H5 HPAI on 14 May.

The total number of birds affected is over 1.76 million, comprising more than 1.11 million chickens and 652,000 turkeys (41,760 hatching eggs).

Overview of high-path avian flu outbreaks in US poultry

The following information is based on published USDA APHIS outbreak reports:

• The latest cases bring the total number of confirmed high-path avian flu outbreaks since December 2014 to 162.
• Outbreaks have occurred in poultry in 15 states.
• Three of the early outbreaks were caused by the H5N8 sub-type of the virus but in almost all those since mid-February 2015, an H5N2 variant of mixed Eurasian and American origin has been confirmed.
• The majority of outbreaks have been in commercial turkeys (116); 29 have been in commercial chickens, one in a mixed commercial flock and 16 in backyard flocks.
• The number of poultry known to have been affected by these outbreaks now exceeds 33.52 million. This figure includes more than 27.53 million commercial chickens and 5.91 million commercial turkeys as well as 7,173 backyard poultry.
• The disease has also affected five captive wild birds.