The virus infected 106 residents and 53 staff members at Selkirk Place since the outbreak began July 11.
While nine people have also died since then, and norovirus may have been a contributing factor, the health authority said the causes of deaths still have to be determined.
"The residents are generally quite elderly and frail and have multiple health conditions," spokeswoman Sarah Plank said in a phone interview. "So they're certainly at risk from it, but generally people don't die of norovirus, but rather with norovirus."
Norovirus is part of a group of viruses that causes severe vomiting and diarrhea. Most people are able to recover after a few days, but for elderly people with chronic illnesses, the highly contagious virus is something their bodies can ill-afford, said chief medical officer Dr. Richard Stanwick.
"What you have is a virus that would give you and I some grief for maybe three days, but for somebody who is struggling with sometimes 10 to 11 medical conditions, this is really just one more thing the body just can't handle," he said.
"Unfortunately what happens is the norovirus creates a stressor and pushes people over into heart failure or other conditions that will ultimately claim their life."
While norovirus is common in the summertime and in long-term care homes, Plank said the outbreak at Selkirk Place was unusually wide-spreading. Forty people became ill within 24 hours of the first case, she said.
"Usually if it's just one or two cases, you can confine it, you isolate the patients and you keep them to their own floor so you can contain the outbreak to just one floor or one unit," she said.
"But in this one, because there was such a large number of people who became ill so quickly, it spread to more people than we would normally see."
Stanwick said the norovirus that swept through Selkirk Place was likely "the garden variety," and not a new, nastier strain that was detected in Australia and the U.S. last year.
However, the fact that so many people became ill so rapidly is concerning, and suggests the virus came from a common source, he said.
"From time to time, we do eventually discover that somebody had a sick child who came in, who was just feeling a little off," he said.
"It doesn't always present as this violent illness, but it's enough that they can actually shed the virus and unknowingly pass it on because they're so mildly ill, they didn't realize they had a norovirus infection."
Stanwick said the health authority will be investigating who at the Victoria care home may have been sick prior to the outbreak, as well as whether anyone who may have had the virus was handling the facility's food.
Plank said staff at Selkirk Place did everything they could to control the outbreak, including isolating sick residents in their rooms, doing additional cleaning, restricting visitors, rescheduling hospital visits, and allowing only healthy residents to dine in common areas.
Eleven people remain ill at the care home, but Plank said she believes the outbreak has peaked, and the worst is over.
Still, Stanwick warns that norovirus is still circulating in the community, causing at least one summer camp on Vancouver Island to send children home after an outbreak.
"Wash your hands," he advised. "That's probably the best defence."
--By Vivian Luk in Vancouver
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