Visitors to residential care or assisted living facilities must wear a mask and wash their hands if they have not had a flu shot. (Stephen M. Katz/Associated Press)

The flu is so bad in Metro Vancouver this year that officials in one area have declared it a public health hazard and are invoking special measures to fight its spread.

The Fraser Health Authority says there have been twice as many influenza outbreaks so far this winter as the last three years combined and more than three times the number of deaths among people in residential care facilities.

It says there have been 19 outbreaks at long-term care facilities in the Fraser region, while flu-related visits to area emergency departments are at the highest level in years.

Chief medical health officer Dr. Paul Van Buynder says declaring the illness a health hazard under the Public Health Act allows the use of extra measures to help protect the community's most vulnerable residents.

The measures include requiring visitors to a residential care or assisted living facility to wear a mask and wash their hands if they have not had a flu shot.

Fraser Health says anyone who's not feeling well should not visit such facilities.