http://www.thenation.com/doc/20100510/coyne
"Imagine for a moment that a large proportion of Americans--let's say half--rejected the "germ theory" of infectious disease. Maladies like swine flu, malaria and AIDS aren't caused by micro-organisms, they claim, but by the displeasure of gods, whom they propitiate by praying, consulting shamans and sacrificing goats. Now, you'd surely find this a national disgrace, for those people would be utterly, unequivocally wrong. Although it's called germ theory, the idea that infections are spread by small creatures is also a fact, supported by mountains of evidence. You don't get malaria unless you carry a specific protozoan parasite. ....."