COVID-19: Part 7

March 20, 2020 2:45 pm
  • U.S./Mexico border closed.
  • Illinois puts in place a shelter-at-home directive.
  • New York puts in place a not-quite shelter-at-home directive. If it expands to a shelter-at-home directive (which it likely will) it, with Illinois and California, would put ~22% of the U.S. population under shelter-at-home directives.
  • The State Department shuts down visa services and advises U.S. residents to not leave the country and if abroad to return home immediately or prepare to stay where they are indefinitely.
  • As additional economic-bailout-measures are debated, states are enacting moratoriums on evictions; moratoriums on utility disconnects have already be enacted in many places.
  • Between loss of demand and increased production by Russia and Saudi Arabia oil prices have collapsed. WTI is trading at ~$20/barrel, down from ~$60 in January.
  • Financial firms are forecasting GDP drops of 10-24% per quarter.
  • DJIA down another 4.5% today.
  • Alameda County is reporting 45 cases as of today.

It appears that much of the rapid implementation of strong isolation requirements is due to the release of this report dated March 16 from the WHO Collaborating Centre for Infectious Disease Modelling, MRC Centre for Global Infectious Disease Analysis, Abdul Latif Jameel Institute for Disease and Emergency Analytics, Imperial College London. This is apparently a very well respected epidemiology group.

The report is...I'll say "sobering" rather than "terrifying" (oh, too late). It describes three broad scenarios of response: do nothing special, "mitigation", and "suppression" (further broken down into particular measures). Using the best available information and filling in the gaps with their own expert-based opinions the team performed computer modeling of how the disease would affect the U.K. and the U.S.

The "do nothing special" category suggests 2.2 million U.S. deaths; peaking in late June and ICUs already being overwhelmed by mid April.

Applying "mitigation" measures over a three-month period suggests that number could be reduced to 1.1 million U.S. deaths.

We therefore conclude that epidemic suppression is the only viable strategy at the current time. The social and economic effects of the measures which are needed to achieve this policy goal will be profound.

From the summary:

We show that in the UK and US context, suppression will minimally require a combination of social distancing of the entire population, home isolation of cases and household quarantine of their family members. This may need to be supplemented by school and university closures, though it should be recognised that such closures may have negative impacts on health systems due to increased absenteeism. The major challenge of suppression is that this type of intensive intervention package – or something equivalently effective at reducing transmission – will need to be maintained until a vaccine becomes available (potentially 18 months or more) – given that we predict that transmission will quickly rebound if interventions are relaxed. We show that intermittent social distancing – triggered by trends in disease surveillance – may allow interventions to be relaxed temporarily in relative short time windows, but measures will need to be reintroduced if or when case numbers rebound. Last, while experience in China and now South Korea show that suppression is possible in the short term, it remains to be seen whether it is possible long-term, and whether the social and economic costs of the interventions adopted thus far can be reduced.

And this is what has the world freaking out. Governments were reading this report on Monday (and presumably inside groups were being briefed on the findings before the report was completed).

Note: I can't find an explicit statement in the report of the modeled death count when applying "suppression" measures. They have a complicated chart with technical language I'm not versed in and am not sure how to read.

With "suppression" measures in place, the modeling suggests U.S. ICUs being overwhelmed in early August, but only by 40% rather than the 1500% in the "do nothing" approach. This assumes the full suppression measures are in force by early April.

With that modeling, under a best-case scenario the worst of it is still weeks away and when the suppression measures are lifted we'll still get clobbered about 6 weeks later, requiring waves of suppression.

However, we emphasise that [it] is not at all certain that suppression will succeed long term; no public health intervention with such disruptive effects on society has been previously attempted for such a long duration of time. How populations and societies will respond remains unclear.

So, yah. That's not comforting. Of course, it's possible that this analysis is fundamentally flawed. As more data (especially testing) becomes available these models will be updated and re-run. Until then, this seems to be the best information available. And when the best information available says that even with mitigation measures a million people are going to die then people start freaking out.

Here's a picture of some flowers I saw on my walk today. Deep breath.

I spent my work day implementing tests for code that will populate names for active users and clean up duplicate accounts. Feels super relevant.

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