"Dr. David Nabarro, chief avian flu coordinator for the United Nations, has become gun-shy about making predictions - in particular about if and when the A(H5N1) virus, now devastating bird populations around the world, will do the same to humans.

But Dr. Nabarro describes himself as "quite scared," especially since the disease has broken out of Asia and reached birds in Africa, Europe and India much faster than he expected it to. "That rampant, explosive spread," he said, "and the dramatic way it's killing poultry so rapidly suggests that we've got a very beastly virus in our midst." [Read more]