In this Wednesday, Sept. 8, 2010 photo, a Cattail mosquito is held up for inspection at the Maine Medical Center Research Institute in South Portland, Maine. Cattail mosquitos can transmit Eastern equine encephalitis and West Nile virus to humans.

An adult in New Hampshire who tested positive for eastern equine encephalitis virus (EEEV) infection was hospitalized due to severe central nervous system disease and died, state health officials announced.