Federal officials prepared to vaccinate 5,000 people at an Indian reservation Thursday as the nation's largest current outbreak of meningitis claimed a fifth victim.

A 17-year-old girl died early Wednesday, becoming the fifth victim in south-central Washington this year. Seventeen people, mostly children, have contracted meningitis or another form of meningococcal disease since Jan. 10."It is very tragic and we are very concerned," said Linda Topel, assistant director of the Yakima County Health District. "We are in an outbreak situation."

Although there are isolated cases of meningococcal disease around the country all the time, the Yakima outbreak is the largest current cluster, said Dr. Anne Schuchat of the Centers of Disease Control.