Thoughts on the Road to Zero

One of the interesting things to do with exponential growth is how it affects curves not just on the way up, but also on the way back down. This is important when trying to understand where we in Australia are right now especially with daily growth diminishing as rapidly as it is and signs that we’re at the end of this lock-down tunnel as each day passes.

TL;DR

1. We need to look at our Covid19 journey as a game of 2 halves — a Growth phase we passed on March 25 and a Decline phase we’re in the middle of now
2. Close scrutiny of the decline phase is required if we want to get to ZERO cases
3. We need to continue the testing — random testing, testing those with no signs of the disease. Our numbers look good so far but we need to continue
4. Contact tracing apps require proper usage and sing up. Without this they will fail
5. An alternative to contact tracing is a boots on the ground method but technology is not out of the picture on that.

A game of 2 halves

Whilst there is a lot to be positive about and it’s amazing to see how well we’ve done compared to other countries, there is a danger of complacency and thinking that the road out is going to be as easy as the road into this mess. Shutting down businesses and furloughing workers was done so quickly. Getting the economic engine started again won’t be so quick for some organisations but that’s another story.

As we move out, we need to shift our thinking and look at our curve as being made of 2 halves, the Growth phase and the Decline phase. Looking at the data this way was highlighted to me by discussions I’ve had with others in the analytics industry. There are some amazing people out there doing work on trying to understand this once in a lifetime event.

This analysis began by looking at NSW to begin with and in particular, the new cases we were seeing every day, the Daily growth and 3-day growth as well as the days it was taking to double. What was clear was that on the 25th March, the data started to to improve for those measures. In the days leading up to that we were in a growth phase. You can see this improvement in the cells I’ve highlighted below.

So, if we consider March 25th as the period that we moved from the Growth to the Decline phase and splitting up daily cases on a chart would look like this for NSW.

Focusing on the decline phase shows how we are working our way out (the aim is to get to ZERO)

It looks fine there but on a Log scale we can see that we may still be prone to a few flare ups.

I took this same analysis to the national level for Australia. We also have the 2 halves of Growth and Decline.

The national Decline curve is also on a downward trajectory.

And we also have an issue around the small figures still showing spikes when you see it above and on a logarithmic scale it is enhanced further.

The way down is clearly not so straight forward so we need to keep at it and hold out just a bit more whilst we are so close to flattening this thing.

What happens next?

When we look at data since Easter (April 12th) the average number of new cases per day for NSW is down to 13 with only 6 new cases yesterday. For Australia this is an average of 38 with only 14 new cases overnight. These are far lower levels than what we had seen in the days/weeks prior.

Does this mean that we’re out of the woods with this disease? On the one hand it’s unlikely especially considering how contagious this disease has proven to be (higher R0 figures compared to other viruses can attest to that). So it is reasonable to think that we’re likely to have undiagnosed cases out in the wild. The problem with this is that the asymptomatic persons who have the virus who might pass on the virus to others who also are asymptomatic and eventually spread the disease to those who will have far more serious health consequences.

On the other hand, test results we’ve had to date have appeared to max out at 2% positive cases per tests performed and over the weekend there were 30,000 tests performed and only 83 new cases confirmed (per this AFR article I also reference later: https://www.afr.com/policy/health-and-education/milestone-day-for-low-infections-raises-hopes-of-lockdown-easing-20200420-p54lfx).

Whatever happens next we know for sure that we need to do more testing and that we also need more contact tracing.

Testing

Douglas Isles, who I interviewed in this blog ( https://medium.com/prosperity-advisers-dna/interview-douglas-isles-investment-specialist-platinum-asset-management-d1b34ddba841) has been pushing for more testing and has even had his own stint in the news on this (last Friday on Channel Ten). He shared with me an article by another actuary, Jennifer Lang (http://actuarialeye.com/2020/04/20/covid19-reflections-25/) who highlighted the issues around how many asmyptomatic carriers are potentially out there citing research from the city of Vo in Italy (https://www.medrxiv.org/content/10.1101/2020.04.17.20053157v1.full.pdf). This research found that the disease had been spreading across asymptomatic persons so continued suppression, lock-down social distancing practices were needed. What is also needed is a good level of random testing and contact tracing too.

Since we know that asymptomatic transmission can occur its right for the governments to expand testing criteria to ensure we cover off any potentially asymptomatic transmissions here in NSW and Australia. We can see testing data as provided on the Australian Financial Review Coronavirus data blog run by Edmund Tadros and team (LINK).

Additionally from the AFR, there is another article that Ed wrote alongside health writer Jill Margo looking at the road to recovery (https://www.afr.com/policy/health-and-education/milestone-day-for-low-infections-raises-hopes-of-lockdown-easing-20200420-p54lfx). In it we see a quote on the need for more testing by Biosecurity Professor Andrew Robinson who stated the following:

“But, until we sample and test the low-risk populations, it’s impossible to say anything about the rest of the cases. The gold standard for testing whether risk factors are accurate requires us to extensively test subjects that are not considered risky, which seems like a paradox.”

Whether we have undiagnosed asymptomatic transmissions in the wild will only be covered by more testing. In Vo, Italy they tested 3% of the population (including those not showing signs of the virus) to ensure a better chance at stopping the spread. In Australia, 3% would be 750,000 people. We’ve so far tested 439,000 in Australia so we’re on our way but still have more to go.

Contact tracing

Even with more testing, it’s not enough on its own. We also need need to have better contact tracing. I highlighted in another recent article the issues around manual contact tracing that Singapore has (https://medium.com/prosperity-advisers-dna/coronavirus-were-getting-ready-to-dance-8a7a92d4acb0). This article was based on recent work by Tomas Pueyo which you can see more of here (Coronavirus — Learning how to dance).

In Pueyo’s article he highlights Singapore where they’re releasing an app to help ease the burden of what was manual contact tracing. But, these apps only work when there is good usage and take up. Singapore residents trust their government but even then, they’ve only got 20% take up of their app (TraceTogether). When tracing is effective, you get to see insights like below where a node (representing a confirmed case) is clicked on which shows a good deal of information about the case (without confidentiality being breached of course).

But when there’s a lack of take up or poor usage, the app shows nothing on a confirmed case node and this would make tracing contacts potentially affected by the virus difficult.

Getting people to use apps to enable better tracing is going to be hard even at the 20% take up levels as the only way the technology works is if a random person using the app (20% chance of someone using it in Singapore’s case) meets another random person also using the app (20%) and the overall chances of this happening are only 4% (20% x 20%).

Given how Australia’s government is already seeing backlash against the idea of a contact tracing app monitoring movements for Aussie residents, it’s a wonder how we’ll get to the 40% that PM Scott Morrison requires for us to ease restrictions, especially when Singapore can’t even get this figure higher itself.

An anti-technology solution perhaps?

With issues like this perhaps it’s better to think about a boots on the ground approach. This is weird to say from someone like me who’s an advocate of technology but first and foremost I’m about the data. If collecting better data requires a new way of thinking so be it.

In order to achieve more contact tracing we need bodies out there doing the manual work to help us understand. This is an idea that was posed to me by economist John Greenan who I recently interviewed (https://medium.com/prosperity-advisers-dna/interview-john-greenan-ceo-alignment-systems-a62a248a79f5 ). In my conversation with John, he quoted T.R. Fehrenbach who wrote the following about the Korean War:

“Americans in 1950 rediscovered something that since Hiroshima they had forgotten: you may fly over a land forever; you may bomb it, atomize it, pulverize it and wipe it clean of life — but if you desire to defend it, protect it, and keep it for civilization, you must do this on the ground, the way the Roman legions did, by putting your young men into the mud.”

His point is that we would do better to use manpower to do this contact tracing especially when the technology approach only works when people sign up.

Now where could we find a cohort of recently unemployed persons who could help us better contact trace? According to the Grattan Institute, 3.4 million Australians could be out of work. Even if a fraction of that was used it is surely something that could help ease the burden on states like South Australia which reported on April 1 that it had 140 people in the contact tracing unit it created with another 300 ready to be added.

Not everyone is an epidemiologist, I get that, although there could be some training that’s done to help people simply collect the data and ask a set of questions that branches to other questions depending on answers given. There’s already proven points around using the wisdom of the crowds to solve other large scale problems such as this crowd-sourced Astronomy project Galaxy Zoo (https://en.wikipedia.org/wiki/Galaxy_Zoo).

Technology does not have to be left in the dark here either. With the help of epidemiologists, an app that helps advise these helper-epidemiologists as to what to say and ask is going to help us not just get the quantity of data we’re after but also ensure it’s quality.

Additionally, the federal and state governments can create a program here to support those recently furloughed and laid off staff who could potentially help with contact tracing.

The push-back on forcing people to use a government app is already difficult. Alternative solutions are out there. This is something the government has to also tackle and will be another one of many potential bumps in the road on the way down to ZERO.