[Gary] Butcher has been an extension veterinarian at the University of Florida's College of Veterinary Medicine since 1988. He was trained as a veterinarian specializing in avian diseases, and has a Ph.D. in poultry virology. Butcher begins his presentation with a slide that shows a news flash" from the British press agency Reuters reporting that avian flu "poses the single biggest threat to the world right now." So far, however...no one has yet been proven to have given avian influenza to someone else. "The emphasis of all my work has changed to dealing with this madness," Butcher said Friday. "Realistically, avian influenza is not a threat to people, but everywhere you go, it has turned into a circus." Millions of chickens and waterfowl have been slaughtered in Asia...but Butcher said that of the billions of people who have probably been exposed, only about 120 have been reported to have fallen ill with avian flu. They were people who worked closely with chickens and came into contact with the birds' blood and feces. Not all health officials are sounding a warning about avian influenza, either. Dr. Marc Siegel, a practicing internist and associate professor of medicine at the New York University School of Medicine...isn't buying into the scare scenario. "If anything is contagious right now, it's judgment clouded by fear," Siegel said. [Butcher] said that although there is a potential that the virus could mutate, as it exists, it could not become an important disease in humans. "For it to become dangerous to humans, it has to go through a pretty significant genetic change. If you put this in perspective, it's not going to happen.