What is the Avian Influenza A (H5N1) virus? 

Avian Influenza A is a contagious viral infection that primarily affects birds. The virus is widespread in wild birds around the world.  Recently, it has begun causing outbreaks among U.S. poultry and dairy cows, with human cases emerging in poultry and dairy workers. Status (updated 12-31-2024): 

• In the U.S., all 50 states have reported outbreaks in poultry, with over 125 million birds affected.

• Since March 2024, infections have been reported in dairy herds, with 913 herds affected across 16 states. 

• In 2024, the CDC has confirmed 66 humans cases in the U.S. The majority of these cases have been associated with exposure to infected poultry (23) or dairy cattle (40). 

Where can I find information? 

• FAO’s Preliminary rapid risk assessment of foodborne avian influenza A (H5N1) virus: Takeaways from the risk assessment include: 
  • Negligible risk of foodborne transmission: The rapid risk assessment reports negligible risk through foodborne transition as the avian influenza A does not transmit to humans via food based on limited presence and potential reductions. However, there may be special circumstances, such as raw meat, undercooked eggs and unpasteurized raw milk.  

• CDC Recommendations page: The Center for Disease Control and Prevention (CDC) has issued interim recommendations to mitigate human exposure. Recommendations include: 
  • Avoid Direct Contact: Individuals should avoid direct contact with wild birds, sick or dead poultry and potentially contaminated environments. 
  • Use of Personal Protective Equipment (PPE): For those involved in culling infected animals or responding to outbreaks, the CDC recommends using appropriate PPE, including respirators, gloves and eye protection, to reduce the risk of infection. 

• FDA Investigation of Avian Influenza A (H5N1) Virus in Dairy Cattle: Updates by the FDA on the investigation of the outbreak affecting poultry, dairy cows and humans across multiple states. 

• CDC Prevention of Avian Influenza A in People 

How does the Avian Influenza A virus transfer to humans? 

The CDC has a resource page on what causes Avian Influenza A transfer to humans. It is worth noting that Avian Influenza A infections in humans are rare. In 2024, 66 human cases have been confirmed, all associated to exposure to infected poultry or cattle. 

Infected birds will shed avian influenza through saliva, mucous and feces. Other infected animals may have the virus present in respiratory secretions, different organs, blood or in other bodily fluids, including animal milk. Human infections happen when the virus gets into the eyes, nose, mouth or is inhaled.  

The CDC recommends avoiding: 

• Direct exposure to infected birds (handling, slaughtering). 

• Contact with contaminated surfaces or inhalation of aerosols in proximity. 

• Consuming raw milk or raw milk products, especially from animals with confirmed or suspected avian influenza A virus infection. 

The FAO risk assessment highlights that cells that express the preferential receptors for avian influenza A (H5N1) and permit the virus to enter and replicate are not reported in the human digestive tract. 

What should growers do? 

While the risk for foodborne transmission is negligible, produce can still be contaminated with the virus through bird droppings.  

Growers should establish food safety practices to prevent contamination from animals. These food safety practices include but are not limited to: 

• Evaluating and monitoring animal activity in and proximate to the produce fields and production environments. This may include monitoring during the pre-season, pre-harvest and during harvest. When animals present a probable risk, take actions to reduce their access to the fields and production environments. 

• Training employees to recognize and report evidence of animal activity. 

• Consider fencing, barriers, noisemakers and other practices to reduce intrusions. Keep in mind that changes to the habitat may result in adverse impact to the environment. It is recommended that growers check for local, state and federal laws regarding control measures. 

Is food safe to be consumed?  

Fresh produce is not considered to be a concern for avian influenza A, however, the FAO has identified the risk of foodborne avian influenza A negligible. Foodborne transmission has not been confirmed, exposure is limited and control measures are effective.  

Both the FAO and CDC highlight that raw meat, undercooked eggs and unpasteurized raw milk are exemptions for potential contamination. Below is information provided by the CDC regarding these foods.  

Eating improperly cooked poultry, beef or unpasteurized milk products can pose serious health risks. Here are the key points to ensure food safety: 

• Poultry Safety: 
  • Cook poultry and eggs to an internal temperature of 165°F to kill bacteria and viruses, including avian influenza A viruses. 
  • Keep raw poultry separate from cooked foods and those not intended for cooking. 

• Beef Safety: 
  • Cook ground beef to 160°F and whole cuts to 145°F with a 3-minute rest period. 
  • Prevent cross-contamination by separating raw beef from ready-to-eat foods. 

• Milk Safety: 
  • Always choose pasteurized milk and dairy products to avoid harmful bacteria and viruses. 
  • Unpasteurized (raw) milk and products made from it, like soft cheese, can cause severe illness. There is no evidence avian influenza A viruses can be transmitted via raw milk, but caution is advised. 

Where can I go for additional information? 

• Send us an email at [email protected].  

• Check the FDA page for updates. 

• Check the CDC webpage for updates. 

• Check the USDA webpage for updates. 

• Review LGMA best practices for information on dealing with animal hazards.  

• Cornell’s wildlife and animal management: IN 202 for SOPs and Decision Trees.  

• USDA’s Updates to Indemnity Program for Highly Pathogenic Avian Influenza on Poultry Farms