Nine people have died at a Victoria seniors' home where half the patients and staff have been infected with norovirus over recent weeks.

The Vancouver Island Health Authority has yet to confirm the causes of death, but said each has occurred since the outbreak was discovered at the Selkirk Place Care Facility on July 11.

About half the residents at the 200-person home are sick, as are 50 staff members, and three people have been hospitalized this month.

Norovirus is highly contagious. Officials say up to 50 per cent of those exposed will develop symptoms, which can include episodes of nausea, vomiting and diarrhea, sometimes accompanied by abdominal pain and tenderness.

Common causes of infection include:

  • Eating food or drinking liquid contaminated with norovirus. Shellfish and salad ingredients are the most commonly-infected foods.
  • Touching objects contaminated with norovirus then putting your hand in your mouth.
  • Having direct contact, such as sharing foods or utensils, with someone who is infected.

There is no vaccine or medicine that can prevent norovirus.