Oct 8, 2007
Michael Nicholson, from Livingston, West Lothian, contracted the rare Triple E bug from a mosquito bite in the US, his family said.
It is thought the 35-year-old painter and decorator was bitten while fishing in New Hampshire this summer.
Mr Nicholson's relatives say that if he lives he is expected to be severely disabled for the rest of his life.
He is being treated in Edinburgh's Western General Hospital.
The virus, known as Eastern Equine Encephalitis or Triple E, is regarded as one of the most serious mosquito-borne diseases on the North American continent.
It is found mainly in the eastern regions of the US and has a 35% mortality rate.
Symptoms develop after three to 10 days, and include flu-like illness, inflammation of the brain, coma and death.
Michael's sister Sharan McKenzie, also from Livingston, said she wanted to warn other holidaymakers travelling to New England about the dangers of the virus.
British tourists heading to the area are given no official warnings about the potential risk, she said.
Michael Nicholson was bitten while fishing in New Hampshire
Mrs McKenzie, 38, said: "There is no cure and there is no vaccine, so all you can do is try and prevent yourself being bitten.
"You don't think there is going to be a risk if you get bitten by a mosquito in somewhere like the US, or Spain.
"So we had no idea this would be so devastating.
"The more people know about this the better."
Mr Nicholson spent six weeks with family and friends in Rhode Island and New Hampshire this summer.
He fell ill on 31 August, a day after flying back to Scotland.
Within two days he had lost consciousness and was transferred to the intensive care unit at the Western General.
Mrs McKenzie said doctors diagnosed her brother with Triple E on 13 September, telling the family his was the first case in Europe.
She said Michael was now in the hospital's neurological unit where he remained unconscious and unresponsive.
"He has opened his eyes, but is not aware of anything," Mrs McKenzie said.
"Our family has been devastated by this.
"We have been told he is likely to be severely disabled at best.
"It seems there is nothing we can do apart from warn people."
Dr Lorna Willocks, NHS Lothian consultant in public health, said: "We are aware of a case of Eastern Equine Encephalitis (EEE) where the patient had recently returned from the US.
"EEE is an extremely rare disease which has never been transmitted from person to person, and it can only be caught through bites from infected insects. The virus is not found in the UK."
US health records reveal 220 confirmed cases of Triple E between 1964 and 2004, an average of five per year.