Untangling the mysterious transmission of avian influenza between dairy cattle and poultry stands as one of today's most pressing One Health challenges. Two researchers from The Ohio State University, Dr. Scott Kenney and PhD candidate Carolyn Lee, take us deep into their research in this area.

Their research reveals that just 10 viral particles can establish an infection in dairy cattle, multiplying to 700 billion particles in milk within mere days. As Dr. Kenney explains, a single infected dairy herd could theoretically produce enough virus "to kill every chicken in the world 17 million times." These astronomical quantities help explain why containing spread has proven so difficult.

What makes this outbreak particularly unusual is how the virus behaves differently in cattle than in birds. While avian influenza typically causes severe respiratory disease in poultry, in cattle it primarily targets the mammary gland. Infected cows don't cough or show traditional flu symptoms – instead, they experience dramatic drops in milk production while continuing to shed massive viral loads. Surprisingly, when the researchers housed chickens and infected cattle together, transmission didn't occur, suggesting farm-to-farm spread likely happens through contaminated objects rather than air.

The conversation takes a critical turn toward biosecurity practices on dairy and poultry farms. As we face the unprecedented reality of two separate avian influenza introductions into U.S. dairy herds in a single year, the researchers emphasize the urgent need for enhanced surveillance, strict biosecurity measures, and continued research into potential vaccines.

Your hosts for this episode of ONE Health Live are Sarah Muirhead and Dennis Erpelding of Global Farm View.