It seems an age ago that I was singing the praises of Singapore, who had handled the coronavirus in a highly pragmatic way. In brief, citizens were asked to take their own temperatures and if they were above normal, isolate themselves and be tested for coronavirus. Frequent hand washing and the use of masks helped reduce transmission.
Since posting that on 26 February much has changed. Country after country has been set the IQ test, and the results have varied. China, Singapore, Taiwan, South Korea and Japan are well ranked, though China may have cheated. Italy and Spain are towards bottom of the class. Sweden’s results are still being marked, but very much worth watching. Holland has also tried an intelligent, adult approach, with many shops open, but as death rates rise may move to more severe lockdown. The US is a new arrival to the class, and will be evaluated in a few week’s time.
Testing is of two sorts: 1) has the person got the active virus, and 2) did they have the virus some time ago, and develop anti-bodies to it. The first group need tracing and isolation; the second group need jobs looking after the first group, or simply to return to their jobs to keep the whole show on the road. The UK seems to have messed up its homework on testing. It knew testing was needed, but then didn’t follow through. It is now playing catchup. This is particularly embarrassing because science is done well in this country, but delivering services at scale is a different matter. Public Health England seems lethargic and inept. Done properly, testing reduces the need for a national lockdown. You have to work hard tracing contacts, and must make selective isolation financially and bureaucratically attractive, but if adopted in advance of a wave of cases, it stops the wave.
Of course, finding a trace of the virus does not mean that it is active and able to infect someone. Yet another virologist has said that even in the homes of Covid-19 positive patients’ active viruses have not been found on any surfaces, not even the household cat.
So, it would appear that most transmission comes from pretty close contact with an infected person. The Uruguayan outbreak, which got one of my friends, has been traced to one visitor who had visited Milan and Madrid, felt ill, then better, took a plane to Uruguay, embraced and kissed guests at a 500 person wedding in a Montevideo suburb (high society weddings are like that) and thus set off a wave of infections. A young woman guest at the wedding passed it on to her work colleague, and that young man passed it on to his mother, my friend. She only in the last few days feels fully recovered, but handled the whole thing very calmly, giving us an account of all the symptoms she experienced.
Prime Minister Boris Johnson, who described his coronavirus symptoms as mild, has had 10 days at home and was admitted to hospital last night, presumably because his condition has worsened. This does not look good, and may have profound political consequences. Boris is a vote-winner, his colleagues far less so. Most UK citizens are no longer in doubt that the “invisible enemy” must be treated with respect. Just under 5000 dead so far, with more to come for a while until the rate starts going down, it is hoped.
A friend in distant Scotland could not understand why colleagues were falling ill in this remote place, and then wondered whether the large number of Chinese students at St Andrews University might have something to do with it. Either that, or someone went skiing.
Despite the general lockdown in Europe, Sweden is carrying on roughly as normal, and looking at the rest of the world with bemusement. Swedish scientists advising the Government say that Covid-19 will not be much different from seasonal flu. However, they are looking at the numbers coming into intensive care, and may change tack if those numbers rise sharply. I am fond of rebels, and wish Sweden well.
It is time to play with toys. What better pastime than to look at simulations as the parameters are altered so as to evaluate the efficacy of different policies. Are the Swedes right, or not? This presentation uses an admittedly simplified model, but is the better for it, because the examples are clearly displayed, and different policy outcomes can be compared.
Here is my brief summary of some of the main points.
The best approach is to identify (by testing) and isolate. Trace contacts, test them all, isolate those who test positive. This has the enormous advantage of keeping the economy going. Since the idea of an economy is to furnish all the things we need, that in itself will boost our health. We will have a variety of foods, plenty of exercise, social interaction and might even meet to discuss new ways of combatting disease. This policy halts the epidemic in its tracks. The virus finds no stepping stone.
However, this requires that everyone takes the test, and that everyone who has the virus gets picked up by the test. It has to have high sensitivity. No or very few false negatives. Frankly, although it would also be nice if it had high specificity, false positives are less of a problem. Sure, it is a nuisance to have to stay home, but it is not the end of the world if you mistakenly have to get to know your family better.
If you don’t have tests, or treatments, you have to use social distancing. Social distancing works if everyone does it, but if only 10% cheat, then the effect is blunted.
One minor upside of this pandemic is that more work will be done on testing infection models. All of them are highly sensitive to variables with large error terms, hence the need for caution in interpretation.
It is a nuisance, to put it mildly, that the last few years have not led to a better understanding of how to model pandemics. If the various institutes had at least agreed upon a standard model, of known efficacy, they could still tout their individual models and compare it with the plain vanilla version. Call it the 1927 model.
On a broader front, this pandemic raises the question: how much of our economy is strictly necessary? The essentials of food growing, processing and distribution probably account for no more than 4% of the working age population. Power generation and basic utilities perhaps another 4%. Perhaps the remnant 92% will all be bloggers.