There are plenty of diseases that we contract from animals, but scientists were convinced that hepatitis A wasn’t one of them. A look at other diseases shows us that we’re wrong—and that bats played a part in passing on the disease to humans.
Materials scientists studying beavers have discovered why the crafty rodents never get cavities: the enamel in their teeth is rich in iron. Iron, they found, resists acid more effectively than fluoride.
People don’t die of the Black Plague in the 21st century — except when they do. And the disease won’t be going away any time soon.
Earlier this month, a high school student in Colorado died of the disease. On average, seven people in the U.S. catch the plague every year; some years, it’s only one, and in other years, it’s as many as 17. Worldwide, the plague strikes about 2,000 people every year, and about 10% of them will die. That’s quite a step down for the disease that killed nearly a third of the population of Medieval Europe in its heyday. But why hasn’t the plague faded quietly into the history books?