Covid-19: Wales is past the peak. But now is not a time to be complacent

Angharad Shaw

Anyone who follows a news story on social media will be familiar with the tendency to be pulled deeper and deeper into a story, and if you’re not careful, to be pulled to the extremes. We know this is dangerous, as it is at these edges where fake news finds its most fertile ground. We are all susceptible to it, whether we like it or not.

As someone with a background in statistical analysis (my PhD was in the area of Bioinformatics), the Covid-19 crisis has been of particular interest to me. Initially inspired by the work of the wonderful @LloydCymru, I realised that I should be contributing my knowledge and skills for the public good, too. And so, since 28th March, I have been contributing my graphs, and an interpretation of them based on my understanding of the statistics, to both toot.wales (@[email protected]) and Twitter (@AngharadHafod).

The data we have to work with are, as I am sure we all realise, not particularly reliable. There is little point in doing statistics with data on the number of cases, because we know that most people suspected to be infected with Covid-19 can’t get a test unless they are admitted to hospital. The only figure we have which is at all reliable is the number of deaths in hospitals, and even that figure comes with caveats – it is only hospital deaths, and it often lags behind (e.g. over Easter, we saw a number of deaths not being reported until Wednesday this week, making Wednesday appear particularly bad, when it was probably fairly average compared to other days over the Easter period).

Putting my graphs, statistics and interpretations online has been an interesting experience. And I am very pleased to say that I have predicted a number of things about right. It’s around three weeks since I said the overall death toll in the UK from this wave would be around 20,000. That, at the time, sounded a lot. But if anything it will turn out to be a slight underestimate, though in the right ballpark.

I also have been predicting the peak to be over the Easter weekend, for some time. This is based on a couple of factors: the pattern taken by other countries (notably Italy, whose curve the UK as a whole has been following almost exactly, with a delay of 14 days), and the infection-to-death times that have been reported by researchers elsewhere (in the region of 18 to 23 days).

Peak

To see how this works, we need to understand the “reproduction rate” R of a virus. If R is greater than 1, then one person infects more than one other person, and the virus therefore spreads out of control until it runs out of people to infect. If it is less than 1, one person infects on average less than one other person, and the virus eventually disappears.

Before lockdown, our R was greater than 1. We know that, because deaths were rising exponentially (doubling roughly every 3 days). After lockdown, I assumed that R would be less than 1. The fact that Italy saw its peak in deaths around 3 weeks after they locked down backed up this belief. And it appears to have been borne out by the reduction in the number of deaths – though slow – that we have seen since Easter.

That statement needs to be immediately qualified, for those who have been watching the data: as referred to above, Wednesday’s figure of 60 deaths in Wales was almost certainly due to late reporting of deaths that occurred over the Easter holiday, and when averaged out with the four days gave a figure of 28: lower than each of the four days prior to that.

Dangerous

Covid-19 came to this house. At least, we assume it did. The doctor diagnosed it, via a phone consultation, with my housemate, earlier last week (the “classic” symptoms). Of course, we will never know for sure unless and until we get some sort of test. We suspected it was here 3 weeks ago. I’ve got away with it with relatively mild symptoms, and am now working on regaining my fitness – but otherwise well.

But the experience, for me, was many times worse because of worry. I had to take a break from Twitter. I skipped a couple of days of doing my analysis, not because I was too ill (though I wasn’t feeling great), but because I couldn’t face it. It was too easy to see all the bad news, and not to see the good news. Of course, as you would expect of a good Plaid Cymru member, I want to take every opportunity to criticise the governments in London and Cardiff.

But we have to do it right, with facts. There’s a mindset out there that doesn’t want to see the good news in the data, but wants to make it appear as bad as possible. That’s dangerous, not just for long term credibility, but for the here and now – the mental health of those with the disease, and those who fear it.

Positive

We are on the downward slope. The speed of the descent will depend on how good we are at maintaining our isolation and social distancing. Our long-term success will, as Adam Price said only yesterday (and I had said some time before – had he noticed?), depend on a strategy of testing, contact tracing, and isolation. The testing has to be in place before R gets above 1 (which it would do, if we simply lifted all restrictions), otherwise we will simply go into another cycle, the deaths will rise again, and we’ll face another lockdown.

The economic cost (which one could be forgiven for thinking is all the Westminster Tory government cares about) of another lockdown would surely be greater than the cost of implementing a proper testing strategy. And of course, for the rest of us, most importantly, it would result in fewer deaths.

Look up, be positive. There is no room for complacency, but the worst is past. At least, it is, if our politicians handle this right from here on.