Infectious Diseases

Updated 06 April 2020

Coronavirus death rate lower than previously thought, study suggests

The number of sudden coronavirus-related deaths paints a grim reality. But research suggests this number is not as horrific as it seems, even though this coronavirus is still deadlier than seasonal flu.

As the number of coronavirus-related deaths climbs, we now know that it's deadlier than seasonal flu, especially given the large number of deaths within a short period of time.

But a new study in the journal The Lancet Infectious Diseases shows that only about 0.66% of those with Covid-19 will probably die – a number lower than earlier estimates.

This new rate includes undetected, asymptomatic cases. The previous death rate, without these cases included in calculations, was calculated much higher at 1.38%.

According to Dr Anthony Fauci, the director of the US National Institute of Allergy and Infectious Diseases, the estimated percentage of Covid-19 deaths was earlier predicted to be 2%, but he did mention it could be lower due to the number of infections that go undetected.

What the study entailed

In this new study, researchers tried to determine the true “infection fatality rate” out of everyone testing positive for the new virus, not only those who show symptoms and are sick enough to be hospitalised.

They looked at how widespread infections were among people repatriated to their home countries from Wuhan – all these people received PCR tests – a test that would determine how many of them were shedding the virus, even when they didn't show symptoms.

The researchers then combined their data with publicly available data on reported cases and deaths worldwide.

The death risk for each age group

The research showed that the death rate differed per age group: in adults 80 and older, 7.8% of those infected are estimated to die, while the number drops in younger age groups. In those younger than 40, the death rate is not higher than 0.16%.

Deaths in children younger than nine years were estimated to be rare with a low fatality rate of just 0.00161%.

"There might be outlying cases that get a lot of media attention, but our analysis very clearly shows that at aged 50 and over, hospitalisation is much more likely than in those under 50, and a greater proportion of cases are likely to be fatal," Azra Ghani, a professor at Imperial College London, and an author of the study, stated.

According to him, understanding how many people are likely to die in a pandemic is a key factor for governments to help take preparation measures.

Don’t compare to flu

Researchers also want to emphasise that the study clearly shows that the death rate, albeit not as high as previously estimated, is still higher than seasonal flu, which stands at 0.1%.

This highlights the importance of physical distancing and taking precautions such as washing your hands.

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