More and more animal diseases are “jumping” the species barrier to infect human beings, and the avian influenza strain H5N1 is no exception (see “Connecting the Dots,” cover story, November/December 2004). According to the World Health Organization (WHO), since 2003, 170 people have contracted avian influenza H5N1, 90 of whom have died. Most of the human cases have occurred in Asia, and in places where people have direct contact with diseased poultry—either on farms or during preparation of the meat.The WHO has documented that the H5N1 virus spread to 13 new countries last February. Azerbaijan, Bulgaria, Greece, Italy, Slovenia, Austria, Iran, Germany, France and Hungary have all found the virus in wild birds. Egypt, India and Nigeria have discovered infected domestic poultry.