Contagious diseases have shaped human history and they remain with us today. As the new coronavirus spreads across mainland China and elsewhere around the globe, such infectious diseases are top of mind for many of us. Here's a look at some of the worst of these infections, from ebola and dengue to the more recent SARS, the new coronavirus and Zika virus. https://www.livescience.com/13694-devastating-infectious-diseases-smallpox-plague.html #science