MINNEAPOLIS - Be watchful of ticks this year, as more are predicted to carry viruses.

Scientists have already said an unusually large abundance of acorns in the northeast two years ago fueled a population boom of white-footed mice last year. Dozens of ticks can attach to a single rodent, feed on its blood and acquire the bacteria that causes Lyme disease.

Now, many are concerned about Powassan virus (POW), associated with fever, vomiting, seizures and memory loss. About half of survivors have permanent neurological symptoms and 10% of all cases are fatal, according to the Centers for Disease Control and Prevention. Symptoms usually show up one week or a month after the tick bite. No vaccines or medications are available to treat or prevent the virus infection, the CDC reports.

The virus is rare. Only 75 cases have been reported thus far -- 20 in Minnesota over the past decade.

"The black-legged tick, what most people know as deer ticks are common in the wooded parts of the state and have been expanding their range to parts of northern Minnesota and western Minnesota where we haven't seen them before," said David Neitzel, Epidemiologist with the Minnesota Department of Health. Neitzel says peak season for ticks is mid-May mid-July when they are feeding.

He says everyone is at risk.

"This is a virus that can be transmitted fairly quickly. When a tick attached to you it can spread the virus within 10 to 15 minutes according to animal studies. Whereas with Lyme disease, the tick needs to be attached for one to two days before the disease transmission occurs," said Neitzel.

Experts say your best bet is to prevent a tick bite. They say avoid brushy areas, wear long sleeves, pants and insect repellant. Also, make sure you do a tick check after being outdoors.