A dairy worker in Texas became infected with H5N1 avian influenza likely during the course of milking cows. A sample of the virus taken from the worker was 100% lethal in ferrets, though it spread inefficiently and does not appear to be continuing to spread. Photo: Althea Dotzour A strain of H5N1 avian influenza virus found in a Texas dairy worker who was infected this spring was able to spread among ferrets through the air, although inefficiently, and killed 100% of infected animals in studies ...