Making sense of the coronavirus pandemic— what the science is telling us, and what you can do to prevent its spread

I’m an infectious disease epidemiologist with a background in new and emerging infections, just like this new coronavirus which is currently sweeping the world.

Over the past few weeks I’ve watched as a lot of fear and misinformation has swirled round the internet, and it occurred to me that a lot of it is there because people simply don’t really understand how the science of new infections works, and why the messages we are hearing seem to be changing every day.

I orginally wrote this article as a Facebook post for friends, but was urged to make it public and it has since been shared >1000 times. So I’m adapting it here so that people without Facebook can read and share alike. I hope it helps to demystify things for you. Note that I’m writing about the current situation in the UK, which will be slightly different depending on where you are and at what point in time you’re reading this. I hope you find it helpful.

(Just to note — you can find my CV on LinkedIn; I am writing in a personal capacity and not affiliated with any organisation. The modelling paper referenced is “Report 9: Impact of Non-Pharmaceutical Intervenions to reduce COVID-19 mortality and healthcare demand” by Ferguson et al at Imperial College, and is available freely online).

THE SCIENCE OF THE SITUATION

More data are in, and the data aren’t very encouraging, sadly. But before I elaborate any further, some background info on what work is being done, both in the UK and internationally, to help stem the tide as much as we can.

In any new and emerging infection, you never know at the start what it’s going to do. You don’t know how good it is at transmitting to other people. You don’t know who’ll be at most risk. You don’t know its fatality rate. You don’t know if people have symptoms before they are infectious, or if they spread it around for a little while before they know they are sick.

Infectious disease epidemiologists are the people who track the emergence in real time, in an effort to work out some rough answers for these questions. We’re also good at looking at what happened in hindsight, which can be used for learning for the future. But in an emerging situation, what you really want to know is not what’s happening right now, nor what happened over the last few weeks: what…