Tuesday, March 24, 2020

A way forward as the present becomes the future

This is Joseph

Mark and I have often talked about next steps in covid-19. It's an active area of correspondence between us. One area of frustration that I have is how the messaging is always focused on the current crisis and not the problems coming next.

For example, masks. Early on in the epidemic we were told masks did not help:
The simplicity of those recommendations is likely unsettling to people anxious to do more to protect themselves, so it’s no surprise that face masks are in short supply—despite the CDC specifically not recommending them for healthy people trying to protect against COVID-19. “It seems kind of intuitively obvious that if you put something—whether it’s a scarf or a mask—in front of your nose and mouth, that will filter out some of these viruses that are floating around out there,” says Dr. William Schaffner, professor of medicine in the division of infectious diseases at Vanderbilt University. The only problem: that’s not effective against respiratory illnesses like the flu and COVID-19. If it were, “the CDC would have recommended it years ago,” he says. “It doesn’t, because it makes science-based recommendations.”
Now the CDC says surgical masks can replace N95 masks under these dire conditions. Not only did the messaging backfire by reducing trust in government, it made it necessary to change messages.

The newest (correct) narrative is that we need to preserve masks for health cure workers in the current crisis. This is, unfortunately, completely correct. They bear extreme risk curves and this equipment is necessary to engage in patient treatment and to preserve the existing work force. The desperate circumstances in the hospitals is an ongoing emergency. Target even apologized for putting masks out for sale -- things are so desperate markets don't work.

But what comes next is what I want to talk about. Some studies suggest social distancing may last 18 months based on an Imperial College report. Countries like the US have invoked things like the defense production act.

But the real key will be the cost of distancing for the poor and disenfranchised. Right now there is a lot of goodwill. Rent is being forgiven or extended. Mortgages will be increased. But even if we halt evictions for the full 18 months, there are going to be some brutal social costs. In the US health insurance is linked to employment, and some small businesses will simply not be able to stay open for 18 months without revenue. People living in small apartments with 5 roommates will be in for a tough time. And most cities lack enough green space for half the population to be outside with appropriate social distancing.

So what else can we try?

Well, the goal of social distancing is to reduce the rate of transmission and flatten the curve. Do you know what else would do that? Compulsory mask wearing when outdoors. Preferably a properly fitted N95 mask.  With big fines for not being masked, training sessions on mask fitting, and free masks for all.

Could this be done?

Well, if it really is going to be 18 months we can make more. Current supplies are pitiful. But we are heading into a recession with a whole bunch of soon to be unemployed workers. What about making more? A lot more?

In the short run this will stop the tragic shortages at hospitals, which are getting worse before they get better. In the medium term this will let us ease some of the restrictions and permit a limited amount of public space use with lower transmission rates. Remember, they aren't magic and there will still be some transmission -- the goal is to lower R0 so that we can control the epidemic and eventually starve it of hosts.

And it is clear medical masks work. Here is a cluster randomized trial of cloth masks versus medical masks in Vietnam looking at respiratory infections.


The control group was wearing masks occasionally:
After providing informed consent, 1607 participants were randomised by ward to three arms: (1) medical masks at all times on their work shift; (2) cloth masks at all times on shift or (3) control arm (standard practice, which may or may not include mask use). Standard practice was used as control because the IRB deemed it unethical to ask participants to not wear a mask.
So consistent mask use seems to help with respiratory illness, relative to only using them for high risk. Now, to be clear, obviously in the face of a shortage they need to be rationed for health care providers. My question is: why don't we alleviate the shortage with increased production?

In the long run I am betting on the biomedical community succeeding with one or more of the multitude of vaccines under development (wikipeda tracks 30), with at least one in phase I trials. There are successful coronavirus vaccines in dogs and something in cats, although the research leaves questions I would want answered in a human trial.

There is more here, about tests and about mitigating long term impacts, but this post is long enough. Maybe a sequel?

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