Man who died from mosquito-borne virus went from 'perfectly healthy to brain dead' in just 9 days

A Michigan man who died from a mosquito-borne virus went from being completely healthy to brain dead within days, WOOD-TV reported.

Gregg McChesney, 64, died last month after contracting Eastern equine encephalitis, a rare brain infection typically transmitted by mosquitos and birds.

The disease — which has now killed three people in Michigan this year — caused McChesney to deteriorate at an alarming rate, his brother Mark McChesney said.

"He was a perfectly healthy, happy human being, and within a matter of nine days he went from perfectly healthy to brain dead," Mark McChesney told WOOD-TV on Tuesday. "All of a sudden he had a seizure and next thing you know, he's in the ER and he just never came out of it."

Mark said he and his brother, a painter who worked for decades at Western Michigan University, seemed lively in the months before his death — which made his quick decline all the more shocking.

"Right off the bat, we were like, 'How could this happen? What did happen?'" Mark told the WOOD-TV. "We just didn't know, and the doctors were just doing everything they could to try to say it was this or that, and they just couldn't figure it out."

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Doctors weren't able to determine the cause of the illness until several days after Gregg's death. Eastern equine encephalitis is fatal in around 30 percent of all cases, according to the CDC.

Mark described his brother as a "great guy" who "loved life," adding that the two shared several hobbies over the years — including art, backpacking and working on their parents' farm. Gregg even wrote a poem for Mark and his wife, which Mark still has hanging in his kitchen.

"Have a happy life, you only get one," the last line says.

The outbreak of Eastern equine encephalitis has infected seven people in Michigan, an uncommonly high rate for a disease that usually only affects seven people in the U.S. in total each year. Many of the state's counties have been forced to cancel outdoor events over the threat of more infections.

"Michigan is currently experiencing its worst Eastern equine encephalitis outbreak in more than a decade," Dr. Joneigh Khaldun, the U.S. Centers for Disease Control and Prevention's chief medical executive, said in a news release. "The ongoing cases reported in humans and animals and the severity of this disease illustrate the importance of taking precautions against mosquito bites."