Powassan encephalitis

[pə-wäsən]
n.
  1. An acute disease of children varying clinically from undifferentiated febrile illness to encephalitis, caused by a tick-borne virus.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.