An outbreak of norovirus has been linked to the deaths of nine people at the Selkirk Place care facility in Victoria this month.

The Vancouver Island Health Authority said although the cause of death in each case has not been determined, it believes the gastrointestinal virus likely contributed.

VIHA confirmed 100 patients, half the population at the facility, are sick, with three having to be hospitalized since July 11.

Norovirus — once known as Norwalk virus — is highly contagious and often spreads in places like schools, cruise ships and nursing homes, especially during the winter.

The stomach bug causes bouts of vomiting and diarrhea which can last for a few days.

A new strain of the virus evolves every two or three years; the latest was identified earlier this year and is known as the Sydney strain.

There are no drugs to treat norovirus itself, although it is important to drink lots of fluids to guard against dehydration.

This latest outbreak comes just two months after 29 people on a cruise ship heading for Vancouver came down with the virus.

Units at the Vancouver General Hospital and New Westminster's Royal Columbian Hospital were forced to close earlier this year after both were hit with norovirus outbreaks.