Covid-19 modellers on the ball, despite Chinese lies

It is now beyond doubt that China has been lying to the world about the numbers of Covid-19 cases in Wuhan. The Lancet estimated that we should multiply all Chinese announcements by a factor of 10, but an even more detailed analysis is provided in online Biopharma mag Stat. Working backwards from cases outside China, Imperial College, advisors to the WHO, estimated some 1,000 to 9,700 cases when China was reporting 440. And so for the 1,700 reported deaths to date – read 17,000.

It now seems beyond doubt that Covid-19 is out and now cannot be contained. In the UK we will stop testing once we have 100 confirmed cases – at this point we will have a pandemic. It is likely it has taken hold in London already and we will see many more cases in the next 7 days. An estimated R0 of 2 to 3 means it spreads very easily – it is highly infectious. How quickly it will spread is determined by the serial interval – the time it takes for people to get sick, and the period during which they can infect others. Toronto University has got a useful online modelling tool with sliders – try reducing the serial interval from 7 to 6 days to see the astonishing effects.

Bottom line is that some 60% of us likely to be infected, and 1% are likely to die prematurely as a result. That’s between 300,000 and 400,000 for the UK. Olders will take the brunt, as will those with impaired lung function or impaired auto-immunity. The only glimmer of good news is that economically we can take the hit; Ross Clark in the Speccie reports that a death toll of this scale will cause GDP to drop only by about 0.75% this year. He compares that to the 3.5% to 6% drop in GDP forecast by George Osborne in 2016 if we voted for Brexit.

The other glimmer of hope is the weather. Pandemic viruses spread best when it’s cold and dry – the warmer and moister the air, the less chance the virus has of being transmitted in droplets. It’s counter-intuitive, but high humidity is a good thing as far as reducing spread. On an personal basis, reducing contacts to the absolute minimum possible is the most effective protection. Not much comfort to those commuting on crowded public transport in London, but for those of us who have the choice, reducing the trip to the shops from twice to once a week and cutting out leisure travel will have a significant effect. Try as much as you can to stay in the 40% who avoid infection, and hope for an early hot Easter.

As for the government, they will have plans for hospitals to maximise survival for those worst hit, but otherwise will pursue a policy of carry on as normal, to minimise economic damage. We’re past the point of heroic action, and into taking the hit. As for the Millennials, for whom this will be their first experience of a mortal threat, let’s see how far that open borders stuff lasts when the death toll in Africa hits the tens of millions.