Tracking COVID-19 in Andalucia and Spain
Created 20/3/2020. Updated 3/4/2020
©James Wimberley, March 2020. May be shared freely, though attribution would be courteous. Any modifications must be noted.
All data as of 2 April 2020. Sources at end.
To keep tabs on the progress of the epidemic I wanted two things:
- a historic table of total cases
- the growth rate.
How bad the epidemic is depends on how fast the infection is growing, and whether or not it slows down.
So I built a table and two charts. The table below just lists the cumulative cases in Spain and Andalucia. It’s obvious that infection is still spreading quickly both in our region and in Spain as a whole.
On the second aspect, I created two charts. These are on a logarithmic scale. The reason is that this shows a constant growth rate as a straight line (though parallel lines on log charts don’t mean that the rate is the same). When the line bends downwards, you can easily see that the growth rate is slowing. If you are an optimist, you can just see the beginning of this. The quarantine was only introduced at the weekend, and since there is a ≈ 5-day incubation, plus a few days for diagnosis, we should not expect to see a significant slowdown before early next week.
Finally I calculated moving 7-day growth rates, for the latest day and the two previous days. This will pick up short-term swings.
So far, the growth rate is 33% less in Andalucia than in Spain as a whole, though the gap is slowly narrowing. This is good news as at worst it will flatten the curve and reduce the burden on hospitals, and at best gives containment a better chance.
I plan to update this page regularly. If you find it useful, think of sending a message of encouragement to James dot Wimberley at gmail dot com. Also if you find a professional source of the same data, so I can give up.
I’m sorry it’s only in English. Adding Spanish would make the updating too much of a burden.
Plateau in Spain continues with downticks if you look hard. Bigger downtick in Andalucia. Half of today’s new cases are in just two highly urbanised regions, Madrid and Catalonia. The lockdown does seem to have prevented a massive expansion in other regions, including ours. I guess relative timing rather than mobility of carriers. Regions that locked down with lower cases stayed that way.
Oof, the spike yesterday in total cases has not been repeated and numbers have fallen back to the plateau. I was premature in calling a peak – I’ll wait for 3 consecutive days of falls before venturing this again.
The ISCIII map shows that Castilla-La Mancha is among the worst-hit regions. It consists of Madrid commuter towns and a vast and very low-density farming plain. Are the cases all in the former? If not, it’s an argument against thinking that modern rural life offers protection.
A mixed bag. The headline total of new cases has hit a new record, and Spain will pass 100,000 cases tomorrow. But the uptick in Andalucia yesterday now indeed looks as if it was just a blip, and the trend has been flat for a week. New cases may be biased by better testing – the data on deaths is the better indicator, and it’s still flat.
Slow decline continues in new cases in Spain and has started in new deaths. If 28 March was the peak in these, and the curve is perfectly symmetrical, the total deaths would come out at 13,000: much better than Italy. The UK target is keeping under 20,000, very similar adjusted for population. But there’s a nasty uptick in new cases in Andalucia. Let’s hope it’s just a blip.
Unambiguous good news! New cases in Spain fell by 20% in one day, in Andalucia by 16%. We have definitely turned the corner IMHO. The timing suggests that this is the result of the lockdown imposed a fortnight ago. More surprisingly, new deaths seem to have gone flat – I would have expected them to keep rising for another week. Hats off to Spanish hospital staff and GPs– they are getting better at treatment, in spite of horrendous overload.
I’ve added new cases and new deaths to the table and charts. This is better for spotting turning points. It definitely looks as if new cases in Spain have peaked. If the downslope is similar to the upslope, this suggests a total caseload of around 140,000. The apparent death rate is very high, perhaps because only hospitalized cases may be reported - 20% if you set new deaths against new cases 1 week back. Total deaths would then be of the order of 30,000. That’s guesswork of course. But it looks as if Spain won’t face a hecatomb of hundreds of thousands.
Have I been doing this all wrong? The Spanish government announced on 21 March that it had bought 640,000 Covid testing kits. This plainly reflects a decision to expand testing beyond hospital settings. This is going to catch an increasing number of mild and asymptomatic cases among key workers and traced contacts. It’s the right policy to cut transmission, but it makes recently reported cases a less reliable indicator of the underlying trends. The bias is in one direction: the trend is better than the indicator suggests.
There is nothing I can do about this, but I have added a chart of deaths. This is the hardest indicator of all. It does however lag. Lancet article: “Recently, WHO reported that the time between symptom onset and death ranged from about 2 weeks to 8 weeks”. Add this to the 5-14 day incubation period, and the lockdown won’t show up in death rates before April.
But the slowdown continues! The 1-day growth rate in reported cases in Spain is down to 14%, and 11% in Andalucia. New daily cases are DOWN from 8,758 to 7,871: we may have seen the first peak. (But I Am Not An Epidemiologist). The 7-day GR gets rid of the noise, and it’s inching steadily down.
Update 25/3 There is no longer any difference in growth rate between Spain as a whole and Andalucia. The Spanish has converged on the lower Andalucian one. Both are now just below 20% in the 7-day average. The 1-day GR is the same, which is disappointing.
Update 23/3 Slowdown continues. 7-day growth rate now <30% for Spain, <20% for Andalucia. Notes/sources on this page restored. ISCIII have added new data to their page on hospitalisations and new cases.
Spain To 16 March: WHO daily situation reports (archive)
From 17 March: Instituto de Salud Carlos III (no archive, can be checked against WHO)
Andalucia: Junta de Andalucia (archive)
* Before 12/3, Andalucian reports only cover new cases and are not consistent. Numbers for recoveries are only given on ISCIII website. The old Andalucian series seems to be misaligned by one day with the national series. I have aligned on the latter. This makes no difference to the growth rate.
Logarithms. Example: take a series growing 10 x at each step. It goes 1, 10, 100, 1000 .. The corresponding base-10 logarithms are 0, 1,2, 3 ... which is obviously linear. Change the base to e, and each term is multiplied by the constant (ln 10) = 2.3. Same thing.