Should COVID-19 Infect Vancouver Island At Projected Rates, Here’s How Many Get Sick

On Wednesday, federal health minister Patty Hajdu said that COVID-19 could ultimately infect between 30% and 70% of the Canadian population. A similar figure was raised by German chancellor Angela Merkel, who on Wednesday said that up to 70% of the German population – some 58 million people – could ultimately contract the virus.

Even at Hajdu’s low-end estimate of 30%, this would mean that 240,000 Vancouver Islanders can expect to contract the virus. In a worse case scenario of 70% infection, 560,000 can be expected to fall ill.

The vast majority of COVID-19 patients recover safely at home. However, at these rates of infection the end result for Canada would be one of the most acute public health disasters of modern times. This is particularly true in coastal British Columbia, which has both an older population and an already overstressed healthcare system.

It’s only been 73 days since COVID-19 was first identified in China’s Hubei province, and it won’t be until long after the pandemic has passed that health professionals will have an accurate gauge on its fatality rate. However, there are a few early studies and estimates that public health professionals can use to project the impact of the virus.

Below, The Capital has taken these estimates and applied them to 2016 census numbers on the Vancouver Island population. The ultimate effects of COVID-19 on the region could be better or worse than the scenarios outlined below, and results will be heavily dependent on how well the island adapts to limiting the spread of infection. However, this is the nature of the virus as we currently understand it.

World Health Organization global average

In a March 3 speech, the director-general of the World Health Organization said that 3.4% of global COVID-19 cases had died. This was based on 3,110 deaths having occurred among 90,893 reported cases.

There are plenty of good reasons to believe this is an overestimate. For one, there is the possibility that some COVID-19 infections are so mild that patients aren’t even noticing them, meaning that health professionals may be vastly underestimating the total number of cases.

However, nine days after the pronouncement, the figure is roughly holding. As of Thursday morning, the world had confirmed 124,518 cases of COVID-19 and 4,607 deaths, which translates into a fatality rate of 3.7%.

If the March 3 figure of 3.4% is applied to Vancouver Island, however, we get fatalities of 8,160 in the case of 30% infection and 19,040 at 70%.

Chinese Center for Disease Control and Prevention (CCDCP) study

Published February 24, this study of 72 314 Chinese cases of COVID-19 is one of the most widely cited reports into the impact of COVID-19. It’s from this paper that we first learned that most cases of COVID-19 are mild (81%), but also that the virus has a disproportionately high death rate among the elderly.

Overall, 2.3% of confirmed cases died of the virus. But while researchers couldn’t find a single child under the age of 9 who had died from COVID-19, among patients 80 years or older the death rate was 14.8%.

If Vancouver Island is infected at a rate of 30%, the CCDCP numbers show that there could be 5,520 total fatalities. At 70%, the total fatalities rise to 12,880.

However, Vancouver Island almost certainly skews older than the population examined in the CCDCP study, with the region being home to 47,270 over the age of 80. If that cohort is infected at a rate of 30%, 2,099 of them could be expected to die. If the infection rate is 70%, the number of fatalities rise among the 80-plus cohort rises to 4,897.

Report of the WHO-China Joint Mission on Coronavirus Disease 2019

Released on February 28, this World Health Organization report is based on the findings of a team of 25 international health experts who spent nine days in the most severely affected areas of China. Their findings were ultimately based on 55,924 laboratory confirmed cases of COVID-19.

The report made a crude fatality rate estimate of 3.8%, but noted that this varied wildly based on where and when a patient had been infected. For someone stricken with COVID-19 in the earliest days of the outbreak in Hubei province, they had as much as a one in 20 chance of dying. In outlying areas of China that saw their first cases after February 1, that fatality rate plummeted to as low as 0.7%. Some of this is due to more effective medical responses to the virus, as well as quarantine measures keeping COVID-19 from particularly vulnerable populations.

Nevertheless, at a crude death rate of 3.8% Vancouver Island would see fatalities of 9,120 at 30% infection and 21,280 at 70%. The WHO team also pegged the fatality rate at 21.9% for those aged 80 or older, which among Vancouver Island’s 80+ cohort would translate to fatalities of 3,106 at 30% infection and 7,246 at 70%.

Infection and fatality rates from the Diamond Princess Cruise Ship

The Diamond Princess cruise ship, which was quarantined off the coast of Japan after a COVID-19 outbreak infected roughly 700 aboard, obviously offers a much smaller dataset than either of the two China studies. But it’s arguably more relevant to Vancouver Island in that it depicts the effects on a population that is both older and living in first-world conditions. A team from the Centre for the Mathematical Modelling of Infectious Diseases reviewed the data from infected passengers and released a preliminary look at the effects.

The good news is that passengers weren’t nearly as hard hit as would have been predicted by the CCDCP study. Researchers broke down COVID-19 cases aboard ship by age, and then compared that against CCDCP data to estimate that the vessel should have suffered 15 deaths. In reality, there were only 7 fatalities among passengers.

All told, researchers estimated that the rough death rate for Diamond Princess passengers showing symptoms of COVID-19 was 2.3%, and 1.2% for everyone infected (including those who contracted the virus and didn’t show symptoms). If the 1.2% figure is bluntly applied to Vancouver Island, that’s 2,880 fatalities at an infection rate of 30% and 6,720 fatalities at 70%.

However, the demographics of a cruise ship differ in a few key ways from Vancouver Island. The average age aboard ship was 58, which is significantly higher than the average age of 45 on Vancouver Island, which would seem to indicate that the island death rate would be even lower. However, a cruise ship is also much less likely to contain passengers with acute health problems, a demographic that is most at risk of dying from COVID-19.