Question: Hello, what fraction of people in the UK have covid-19?

Alex Agrotis answered on 30 Apr 2020:

Hi oscaro!
It’s very difficult to say how many people have COVID-19 at any one time, mainly because we can’t test everyone and we aren’t usually testing people who have no symptoms even though they could be infected.

As of yesterday, the total number of confirmed COVID-19 cases since the outbreak begun was 165,221. But this is only out of the people who have been tested, which is a small fraction of the UK population. It also includes people who have since recovered (or sadly died) from the disease, so that number does not tell us how many people are currently infected.

A scientist from University of Oxford (Prof. Christophe Fraser) was recently on BBC News suggesting that COVID-19 may have actually already infected 3-10% of the UK population, which is between 2 million and 6.6 million people. This is an estimation based on how widely the virus has spread and what we currently know about how it spreads. Since most infections are probably unconfirmed, it is likely that the actual number of cases is closer to this scale, more than 10 times higher than the number of confirmed cases. Again, this does not tell us how many people have the virus right now, but instead how many people have likely had it overall.