PORT ANGELES, Wash. -- Doctors are treating a 55-year-old Seattle-area woman who came into contact with a bat infected with rabies last week in Olympic National Park.

The woman found the bat at her Ozette-area campsite around dusk and was scratched when she knocked it to the ground, the park said in a news release. She found the bat on the ground the next morning and called park workers, who took it to be tested for rabies.

The rabies virus was found, and preventative treatment began for the woman and three park employees.

Officials said the only other known case of rabies in Olympic National Park was in July 1975, when a child was bitten by a bat in the Elwha Valley.

Park officials said the risk of acquiring rabies is extremely low, but the disease is fatal if not treated early after exposure. They said it is "vitally important" to treat any possible threat of exposure seriously.

Anyone observing unusual or aggressive behavior among park wildlife, including bats or other mammals that approach or appear fearless of humans, should inform a park ranger as soon as possible, the park said.