“Early symptoms are going to be very similar to meningitis. Severe headache, fever, nausea, and that's followed by some stiffness in the neck, confusion, seizures. These can start a few days after exposure, but can take up to 12 days,”

Dr. John Brownstein · said date not stated · reported 2026-09-01

Dr. Brownstein described the early symptoms of Naegleria fowleri infection, which can resemble meningitis.