A Michigan man succumbed to a mosquito-borne viral infection called Eastern equine encephalitis. He went from healthy to brain dead in a matter of 9 days after contracting the virus.

Gregg McChesney, 64, was referred to as a "perfectly healthy, happy human being” by his brother Mark McChesney. He told CNN affiliate WOOD that he was hale and hearty less than two weeks before his death on Aug. 19 in the wake of the mosquito-borne virus, CNN reported.

"Within a matter of nine days, he went from perfectly healthy to brain dead. 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," McChesney said.

McChesney revealed that he was working with this brother less than a month before he was taken to the emergency room after the seizure. He told the station, "Late July, he was here at the farm helping me put docks in at the pond."

The station reported that even though Gregg McChesney used to speak very less, he loved life. He even scared off a bear during their backpacking trip and gave a 25-minute toast at his little brother's wedding.

While speaking of his brother’s illness McChesney told the station, "Right off the bat, we were like, 'How could this happen? What did happen?” He also said, "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."

The Michigan Department of Health and Human Services Tuesday disclosed four additional cases of Eastern equine encephalitis in Southwest Michigan resulting in two deaths. Among the seven total cases this year, three deaths among them were mentioned by the state.

Dr. Joneigh Khaldun, the department's chief medical executive and chief deputy for health, said in a news release, "Michigan is currently experiencing its worst Eastern Equine Encephalitis outbreak in more than a decade."

The virus, which is medically known as EEE, is rarely found but highly potent in killing people. This signs of this viral infection include sudden beginning of headache, high fever, chills, and vomiting.