The highly pathogenic avian influenza (HPAI) virus infecting US dairy cattle is remarkably unremarkable and there is no evidence that it has mutated. Last month, the USDA confirmed that a strain of HPAI was detected in dairy cows in Texas and Kansas, causing them to suddenly dry off or produce thick, colostrum-like milk. The condition isn’t associated with deaths as cows mostly recover with supportive measures in around 12 days.
Since the first detections in March, further cases have emerged in the past week, including additional cases in Texas and New Mexico, Michigan, Idaho, and Ohio. Cows were initially considered ‘dead-end hosts’, but detections on a Michigan farm that had taken in cattle from Texas suggested cow-to-cow transmission could not be ruled out. A dairy worker believed to have been in close contact with a sick cow tested positive for the virus, and the person had eye redness as the only symptoms and is isolating while recovering.
Hamberg suggested that these recent detections among cows and the rare case in a human were possible scenarios. He explained that this is still being considered a spillover event, and there is no specific mutation that can point to and say the virus is now mammalian-adapted. Pasteurization inactivates the virus, making commercial milk supplies safe for consumption. There are no fears of milk shortage, with just several herds across all of the US affected by the virus so far.
Dairy brands could benefit from reassuring their consumers about the spread of the virus and the potential impact on the safety of meat and dairy products they consume. Brands can build trust with consumers through clear labeling, certifications, seals, traceability, and supply chain information.
