Ian Goodfellow, a prominent researcher at England’s University of Cambridge, calls norovirus ‘the Ferrari of viruses’ for the speed at which it passes through a large group of people. ‘It can sweep through an environment very, very quickly. You can be feeling quite fine one minute and within several hours suffer continuous vomiting and diarrhea,’ he said. Health officials have grown better at detecting new strains and figuring out which one is the culprit. They now know that norovirus is also the most common cause of food poisoning in the U.S. It’s spread by infected food handlers who don’t do a good job washing their hands after using the bathroom.