Theodore Andreadis, director of The Connecticut Agricultural Experiment Station and head of the Center for Vector Biology & Zoonotic Diseases in Connecticut, told Gizmodo that the concern this year isn’t just about how many people have been diagnosed, but also the fact that it seems to be spreading throughout the eastern U.S. thanks to bugs and birds. “Periodically, you know, you might get an outbreak in Massachusetts, Rhode Island, and not necessarily see it in Connecticut and New Jersey. But this year, it’s really all over the entire region,” Andreadis told Gizmodo. “And we don’t even know how many other people might have developed mild sickness or been exposed to the virus and not developed any symptoms. So it’s really rather extraordinary this season.”