March 10, 2020, by Brigitte Nerlich

Flattening the curve to curb an epidemic

In my last blog post I noted the sudden appearance and wide spread of phrases like ‘flattening, stretching, extending, pushing down, drawing out the curve’ and/or the epidemic, meaning that if we can delay or slow down or ‘lower’ the peak of the epidemic for a while and make ‘it’ less steep, we can buy time for hospitals to get ready for a surge in admissions etc.

This talk and text is sometimes accompanied by a visual image that makes clear what this means, namely a graph of two overlapping curves, one steep (without intervention) and one flatter (with intervention). This graph originated, it seems, with the US Centers for Disease Control and Prevention. As one expert explained, what they want to achieve is: “‘flattening the epidemic curve’ — so that it’s not a big, sudden peak in cases, but it’s a more moderate plateau over time.” Another possible origin of the graph is in an article by Roy Anderson et al. from Imperial College London, in The Lancet.

As one tweeter, using a simpler graph showing the curve flattening noted: “… the reason behind school closures, travel restrictions, and event cancellations… isn’t preventing people from getting infected, but preventing people from getting infected too fast.”

Another tweeter said (using another version of the graph): “This #FlattenTheCurve graph surged to prominence this week. But it didn’t say why it is so bad when medical treatment capacity is overwhelmed -> mortality rate rises. So, here is a small animation that shows the value of early containment and double dividend of delay” – I’ll come back to delay!

Another drew a parallel, curve-wise, between the current pandemic and the 1918 one. Curves suddenly were everywhere and curves became ‘the epidemic’.


The phrase ‘flatten the curve‘ started to follow me round in my head and on Twitter, until it finally became a hashtag and on 8 March Claudia Vickers, using the hashtag, retweeted a tweet by microbiologist and coronavirus communicator Siouxsie Wiles which shows a Gif where the flatting could be seen as ‘happening’ (and there are lots of variations online). This went viral. Have a look – especially at the full article! (And here is a follow-up article)

There are now other animated curves flooding into the internet, such as this one for example. And there will be more. Somebody might want to do a Twitter analysis of that hashtag, that curve and its variations and animations! It is a fascinating new way of talking about an epidemic using words and visualisation in combination in order to make people do things.

Many of those spreading the curve and the gif do so in order to tell people to ‘do their bit’, e.g. hand-washing, social distancing etc., stressing the importance of collective action and collaborative action. I think many people are responding to this (the curve for the Norovirus at the moment, has gone, for example, really low!). Curves, graphs, gifs and animations take on a performative force. But…

Delaying the ‘delay’

All this also reminds me of climate change communication. Twenty years or so ago we were told to do our bit, by for example, not filling our kettle too much, recycling and all that. By contrast, governments did not do much themselves. And at this moment, the UK government seems to delay the ‘delay phase’ of their four-part Covid-19 action plan: contain, delay, research, mitigate, which I find utterly baffling.

The Prime Minister even wondered whether we, as a nation, should just ‘take it on the chin’, This would be a rather radical way of flatting the curve! In effect, he said: “‘One of the theories […] is perhaps you could take it on the chin, take it all in one go and allow coronavirus to move through the population without really taking as many draconian measures’. And, without ruling that out, he airily opined: ‘I think we need to strike a balance’.” All this reminds me eerily of climate change discussions, just at a time when I thought experts were given due credit again in government.

As with climate change, so with an epidemic of Covid-19: Only when small individual actions and big government actions are combined and coordinated effectively, can actions against the virus or climate change succeed.

I agree with what the blog ‘Corona Daily’ said, namely that we should “all mobilise to urge our respective governments to do more while continuing to adapt our personal social behaviour to contain the virus“. We should also urge governments to learn from each other, and that rather quickly! But: “Instead of grabbing the chance to get ahead of the curve by implementing drastic measures our government has announced they are going to wait and see.” (bold added)


And here is the curve in French – wonderful – and here in Spanish and here, if you want to laugh in the face of adversity, in Australian and here in ‘cat’!!

And here the UK government’s version -hmmm

And a Boris metaphor: squash this sombrero

And here is a good simulation you can play with in the Washington Post

Posted in infectious diseases