HOW many of those infected by the coronavirus will die? It is still hard to say for sure, not least because the proportion of deaths will vary depending on local circumstances and how the outbreak is handled.
So what do we know? Last week, WHO director general Tedros Adhanom Ghebreyesus’s take on this was widely reported. “Globally, about 3.4 per cent of reported covid-19 cases have died,” he said.
That statement is correct, but was misunderstood by some as being the true death rate. Dividing the number of deaths by the number of reported cases doesn’t reveal how many will die. This is because some of those recently confirmed to have the coronavirus and included in the reported case count might still die, pushing the true figure up. On the other hand, many people with mild symptoms might be going undiagnosed, pushing it down.
Last month, a study estimated that the fatality rate when infected people without symptoms are included in the case count is around 1 per cent, and this is still thought to be in the right ball park.
It is clear that some countries, including the US and Iran, are missing cases as so few people are being tested. South Korea, by contrast, had tested 190,000 people as of 9 March, with 7478 confirmed cases and 51 deaths.
This means 0.7 per cent of reported cases in South Korea have died so far, which matches what we have seen in China outside of Wuhan. If these places are detecting most cases, the fatality rate will not be much lower than this, though it could be higher if many recently infected people die.
“The case fatality rate for covid-19 is not a fixed number and depends on many factors”
The fatality rate for covid-19 isn’t fixed, and will vary based on many factors. Age is one, with the rate rising from around age 50 and reaching 15 per cent in over-80s, according to data from China. Countries like Niger, with many younger people, may fare better than Japan, where more than a quarter are aged over 65.
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