"The more we look, in a sense, the more we find," says Felicia Keesing, an ecologist at Bard College in upstate New York. "Around here, there's anaplasmosis, babesiosis and a bacterium related to Lyme, which causes similar symptoms."And that's just in the Northeast. In the Midwest, you can find Heartland virus, a new Lyme-like disease and Bourbon virus — which is thought to be spread by ticks but hasn't been proven yet. In the South, there's Southern tick-associated rash illness. Out west, there's a new type of spotted fever. And across a big swath of the country, there's a disease called ehrlichiosis. Most of these diseases are still rare. But one is especially worrying. "It's a scary one," Keesing says. "Our local tick — this blacklegged tick — occasionally carries a deadly virus that's called Powassan virus," says Rick Ostfeld, a disease ecologist at the Cary Institute of Ecosystem Studies in Millbrook, N.Y. Powassan is named after a town in Ontario, Canada, where the virus was discovered in 1958. Now it's here in the U.S. The country records about seven cases each year on the East Coast and in the Upper Midwest. What makes Powassan so dangerous is that it attacks the brain, making it swell up. In about 10 percent of cases, Powassan is deadly. And if you do recover, you have about a 50 percent chance of permanent neurological damage. Read the entire article on NPR.