Covid Reflections #6

Today’s Insight

I’m working with a group of actuaries to put some numbers around possible scenarios for deaths in Australia. There are a lot of people cavalierly talking about this being an “old person’s disease”.  But the information available so far (based on what has happened in China and Italy) suggests that around 20% of the deaths in Australia from this disease would be people of working age – people between 20 and 65. If 20% of the population becomes infected (and that is a big if), there would be around 50,000 deaths in Australia. Around 20% of these, around 10,000, would be between the ages of 20 and 65.

We used the case fatality rates by age used in the Imperial College London study. They’ve taken the work done in China and Italy to come up with some likely case fatality rates by age if you are infected with Covid19. And we chose 20% infection of the population as a sobering number to make us realise what is at stake if we don’t flatten the curve. We don’t have any special insight on the likelihood of that 20% – that’s for the epidemiologists I linked to yesterday. But it illustrates what is at stake.

The study I linked to yesterday suggested half the population would be infected in the next three months, if we took no measures to stop the spread. Even with no social distancing measures, most modellers agree that somewhere around the 60-70% of population mark there will be enough immune people around that it will stop spreading (that “herd immunity” you may have heard about). A 20% infection rate still requires us to radically change our behaviour. I hope we will be able to keep it to a much much lower percentage. So far, that’s been true in China, but we are far from having it under control here in Australia.

The main insight I wanted to show you tonight was that while you are at a much greater risk from this disease if you are over 65, there are likely to be many younger people among the deaths that occur. So we all should be doing what we can to slow it down.

Today’s link

Citymapper has done an index of activity around the world – comparing trips planned yesterday and in the last week with normal usage. I’ve shown the Sydney statistics, but it is a fascinating tour of the level of lockdown around the world. I think the actual percentage overstates how much lockdown there is (most people don’t use a map app for a trip that they do every day), but it certainly gives you a sense of the reduction of activity in cities around the world.

We are comparing trips planned in the Citymapper app to a recent typical usage period. Trips planned (‘Get me somewhere’ and related) are correlated to trips taken (GO mode). We have enough data in our cities where we publish CMI to be confident that it represents a real change. Please tweet @Citymapper for requests.

 

Life Glimpses

After the confusing closure announcements the day before yesterday, my hairdresser decided that now was the time to close for the duration. Dean, the manager, is a fixture of the local community, and he just wasn’t prepared to take the risk of infection either of his staff or his customers, no matter what the rules about a haircut being allowable as long as it was less than 30 minutes (which I’m guessing were made in a room with very few women in it). So they called all their customers, and I went in for one last hair colour before the lockdown we all know is coming sometime soon. That’s the only close contact I’ve had outside my family all week (which seems a bit frivolous), but I hate seeing all these very local businesses having to close and stand down their staff, so at least I was able to give them my custom one last time.

This evening I went for one of my favourite bike rides, along a bike path in the bush near the freeway. There were so many people out enjoying the lovely evening. Every little group was being quite responsible and sticking to their own group, and I don’t think I saw anyone within 1.5 m of a non family member (except when passing briefly) but I couldn’t help thinking of how horrified my brother in Spain would be to see so many people out.

Bit of Beauty

Today’s bit of beauty comes from my bike ride this evening. It’s a picture of the Northbridge suspension bridge. The light is always best in the early evening.