Holding immigrants responsible for various health epidemics has been an American pastime for two centuries argues Alan Kraut, Professor of History at American University. Just as the Irish were wrongly blamed for the cholera epidemic in the 1830's so too were Haitians in Miami branded as AIDS carriers in the 1980's. His new book "Silent Travelers: Germs, Genes, & the "Immigrant Menace"" (Basic Books) traces how immigration policy and health care have been affected by xenophobia and public fears of contamination. (Interview by Marty Moss-Coane)