Smallpox, caused by the variola virus, is a highly contagious disease. It was one of the most lethal diseases ever known to humankind, which killed millions of people before it was eradicated. It is believed to have emerged 3,000 years ago. See the fact file below for more information ...
result of deliberate efforts; intervention measures are no longer needed (e.g. smallpox), and 5) extinction, the specific infectious agent no longer exists in nature or in the laboratory (e.g. none)” (Dowdle, 1998). Read full chapterView PDFExplore book...