Immigrants in American society, according to Alan Kraut (1994), represent the double helix of health and fear. On the one hand, immigrants occasionally have been the bearers of harmful and even fatal diseases; on the other hand, pre-existing ethnic prejudices and public hysteria in the face of diseases led public health officials to create a false linkage between illness and specific immigrant groups. Until the mid or late twentieth century, America adopted exclusionary measures in admitting immigrants to America due to this double helix.
