Avian influenza: Expert talks about spread, risks and response in cows and poultry

Poultry World and sister publication Dairy Global asked Prof Dr Timm Harder, head of WOAH, FAO, and National Reference Laboratory for Avian Influenza at the Friedrich-Loeffler-Institut, to shed some light on the spread of avian influenza in the US. In this Q&A he discusses transmission in dairy cows and poultry, control measures and preventative strategies. We have seen the transfer of highly pathogenic avian influenza from cattle and poultry to humans (in the US). Can you explain reasons