Since first being recorded late last year in China, the Covid-19 coronavirus has spread around the world, and been declared a pandemic by the World Health Organization. However, differences in testing mean that the number of cases may be understated for some countries.
Obviously, larger countries tend to have higher numbers both of cases and of deaths. But there are many other factors in play, such as the demographic profiles of the countries; countries with ageing populations may be hit harder because the disease is more dangerous to older people.
The number of deaths is a more dependable indicator. The disease has hit certain countries, including the US, Brazil, India, Mexico and the UK with particular cruelty.
Johns Hopkins University publishes cases and deaths data for most countries in the world (a notable exception being North Korea, which claims to have had none). But JHU concedes that it collects data from many sources, some of which disagree with each other. Even where the collection is less contentious there are significant differences in the ways countries test, and in the way they report cases and deaths. Belgium, for instance, attributes deaths to Covid-19 if the disease is a suspected cause, even if no test has been carried out.
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