COVID-19 cases rise, deaths steady
Shift in demographics to younger people cited as reason for change
Cases of COVID-19 have been rising since the Canada Day long weekend, but have not led to a similar increase in hospitalizations and deaths, according to figures from the B.C. Centre for Disease Control.
Provincial health officials and scientists say this is almost certainly because many of the recent cases are among younger people, who are less likely to become seriously ill and die from the virus.
“What’s really driving low numbers of hospitalizations and deaths is a change in the demographics of who is getting infected,” said University of B.C. epidemiologist, Daniel Coombs.
This is particularly highlighted in the Interior Health region, where there has been a 30-fold increase in positive tests for COVID-19 in the four weeks ending Aug. 6 compared to the previous four-week period, according to an analysis by Postmedia of data from the B.C. Centre for Disease Control.
During the past month, there were only two additional hospitalizations and no deaths in Interior Health.
The jump in positive tests in the Interior — an increase of 184 cases in the past month, including a oneweek jump of 92 cases — is largely linked to an outbreak in Kelowna, where younger people moved among various parties, often mixing with people they did not know.
But it has also played out in Fraser Health, B.C.’s largest health region with more than 1.9 million people, where cases have more than doubled in the past month compared to the previous month, an increase of 449 cases.
During the month, there were 16 new hospitalizations and no new deaths.
The increase in cases has been more pronounced in the Fraser Health region than in Vancouver Coastal Health.
Fraser Health’s cumulative number of positive COVID -19 cases per 100,000 population surpassed that of Vancouver Health at the end of June. As of Aug. 6, there were 106.6 cases for every 100,000 population in Fraser Health, 92.2 in Vancouver Coastal and 48 in Interior Health.
The difference between Fraser and Vancouver Coastal can also possibly be explained by the fact Fraser skews to a younger population, said Coombs, who has expertise in mathematical models of pandemic growth and control.
The 20-to-29-year-old age group’s proportion of the total population in Fraser Health, which covers municipalities from Burnaby to Hope and to White Rock, is nearly twice that of Vancouver Coastal, which includes Vancouver, Richmond, the North Shore and the Sunshine Coast.
In the past month, data from the B.C. Centre for Disease Control shows the 20-29 age group accounted for one-third of new cases in the province. The share of the age group’s increase was nearly triple its share of the population.
Dr. Elizabeth Brodkin, the Fraser Health Authority’s interim chief medical health officer, also attributed the fact there was not a corresponding increase in hospitalizations and deaths with the rising cases to the demographic shift in infections.
In the very early days, infections resulted from travel, initially in
Vancouver Coastal Health, where there were also deadly outbreaks in long-term care homes for the elderly, noted Brodkin.
Since then infections have largely been community based, and health-care providers have greatly improved their management of COVID-19 in long-term care homes.
Outbreaks have also taken place in work places — more in Fraser Health than in Vancouver Coastal Health — most recently at a blueberry packing plant in Abbotsford.
Brodkin injected a word of caution, saying that low hospitalization and death rates will not continue indefinitely if the public is not careful because everyone has parents, grandparents and other vulnerable people in their families and communities.
“There will be spill over to those more vulnerable,” she said.
In a briefing last week, B.C.’s provincial health officer, Dr. Bonnie Henry, said a party in the Vancouver Coastal Health region had led to as many as 46 COVID-19 cases and resulted in the quarantine of about 400 people.
Similar to the outbreak in Kelowna, there were overlapping social groups involved in the party from both the Vancouver Coastal and Fraser health regions, she said.
Dr. Gerald Da Roza, head of medicine at Royal Columbian Hospital in New Westminster, which is part of Fraser Health, is also preparing for the coming influenza season this fall, which will require testing to sort out who has the flu and who has COVID-19. “I would say right now I would still be thinking optimistically, but it will be interesting when we come into the fall.”