If Lyme disease from ticks doesn’t keep you out of the back country, then a new disease the creatures are carrying might. It’s called the Powassan virus, and health officials say it’s more serious than Lyme’s because it causes inflammation of the brain. Other symptoms include fever, headache, vomiting, weakness, confusion, loss of coordination, speech difficulties and seizures. 15 percent of the virus cases are fatal, and 50 percent of the cases leave victims with permanent neurological damage. As of now, there’s no cure. Officials are seeing most cases of the disease in deer ticks, but ticks that carry the virus make up less than 10 percent of the total tick population.