When Did the Threat of Smallpox Emerge?

LA NOSTRA FAMIGLIA, ITALY—According to a Health Day News report, a new mathematical analysis of the rate of evolution of the virus that causes smallpox suggests that it originated some 3,800 years ago, or 2,000 years earlier than previously thought. Diego Forni of the Eugenio Medea Scientific Institute said that the study confirms that smallpox existed in the ancient world, adding that pox scarring has been observed on ancient Egyptian mummies. The study also suggests that different strains of smallpox all descended from a single common ancestor. Read the original scholarly article about this research in Microbial Genomics. To read about excavations around an English manor once owned by Edward Jenner, pioneer of the smallpox vaccine, go to "Letter from England: The Scientist's Garden."