On Aug. 27, 2024, the New Hampshire Department of Health and Human Services (DHHS) identified an adult who tested positive for Eastern Equine Encephalitis Virus (EEEV) infection, was hospitalized due to severe central nervous system disease, and passed away due to their illness.

EEEV is a rare but serious disease transmitted to people by infected mosquitos. New Hampshire reported its last EEE case in 2014 when it reported three infections, two of which were fatal. EEEV can cause flu-like symptoms such as fever, chills, muscle aches, and joint pain. EEEV can also cause severe neurological disease, such as inflammation of the brain and membranes around the spinal cord (i.e. encephalitis and meningitis).