Highly Pathogenic Avian Influenza Detected in a Flock of Commercial Layer Chickens in Sioux County

DES MOINES, Iowa (May 28, 2024) — The Iowa Department of Agriculture and Land Stewardship and the United States Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) have detected a case of Highly Pathogenic Avian Influenza (HPAI) in Sioux County, Iowa. The affected site is a flock of commercial layer chickens. 

HPAI is a viral disease that affects both wild and domestic bird populations as well as lactating dairy cattle.  HPAI can travel in wild birds without those birds appearing sick, but is often fatal to domestic bird populations, including chickens and turkeys. With supportive care, dairy cattle recover with little to no mortality associated with the disease.

Heightened Biosecurity

The Iowa Department of Agriculture and Land Stewardship is strongly encouraging Iowa poultry producers and dairy farmers to bolster their biosecurity practices and protocols to protect their flocks and herds. The Iowa Department of Agriculture and Land Stewardship has biosecurity recommendations for dairy herds to utilize. In addition, the Department has numerous other biosecurity resources for poultry producers and livestock farms to reference on its website. Farmers or farm workers who interact regularly with both dairy and poultry or who interact frequently with other farm workers in poultry or dairy, should take extra precautions to limit possible transmissions.

Suspected Cases in Poultry

If poultry producers or those with backyard birds suspect signs of HPAI, they should contact their veterinarian immediately. Possible cases must also be reported to the Iowa Department of Agriculture and Land Stewardship at (515) 281-5305.

Clinical signs of HPAI in birds may include: 

• Sudden increase in bird deaths without any clinical signs
• Lethargy and/or lack of energy and appetite
• Decrease in egg production
• Soft, thin-shelled and/or misshapen eggs
• Swelling of the head, eyelids, comb, wattles, and hocks
• Purple/blue discoloration of the wattles, comb, and legs
• Difficulty breathing
• Coughing, sneezing, and/or nasal discharge (runny nose)
• Stumbling and/or falling down
• Diarrhea

Suspected Cases in Dairy

If dairy producers suspect cases of HPAI, they should contact their herd veterinarian immediately. Possible cases must also be reported to the Iowa Department of Agriculture and Land Stewardship at (515) 281-5305. USDA’s federal order regulating the interstate movement of lactating dairy cattle remains in effect. 

Clinical signs of HPAI in dairy may include:

• Decrease in food consumption with a simultaneous decrease in rumination
• Clear nasal discharge
• Drop in milk production
• Tacky or loose feces
• Lethargy
• Dehydration
• Fever
• Thicker, concentrated, colostrum-like milk

Food Safety

It remains safe to enjoy poultry products. As a reminder, consumers should always utilize the proper handling and cooking of eggs and poultry products, including cooking to an internal temperature of 165˚F. It is a longstanding practice that only milk from healthy animals may enter the food supply. There is no concern about the safety of pasteurized milk or dairy products. Pasteurization has continually proven to successfully inactivate bacteria and viruses, like influenza, in milk.

Public Health

Though recent cases of HPAI were confirmed in dairy workers in Texas and Michigan, the Centers for Disease Control (CDC) continues to believe the threat to humans remains low. 

Commercial and Backyard HPAI Detections in Iowa