Sound Science Bite: May 10, 2020. Controlling a Chain Reaction.

You have, no doubt, heard more about the SARS-CoV-2 virus than you could ever care. Nevertheless, with all the coverage, there still seems to be confusion over some things that should not be too hard to grasp. Medical science and experience, for example, show that the way to stop an epidemic is through testing, contact tracing, social distancing, mask use, and quarantining, yet even some officials high in state and national government act as if they don't quite get it.

Another area of confusion has to do with the mortality rate and why we even need to worry about a virus with a mortality rate of 1%, more or less. But consider these points.

• The mortality rate depends on age and health. What can be just a mild cold in a young, healthy person can be life-threatening for someone who is vulnerable. This issue is exacerbated by how transmissible the virus is.


• The mortality rate depends on the level of medical intervention. This was a problem in Italy. Without proper care many more with the disease will die that might have recovered.


• The easy transmission of the virus means a lot of people can come down with serious cases in a very short time, overwhelming medical resources. This also means there is a high probability of health providers coming down with the disease. The mortality rate could soar. (See the point just above.)


• Bottom line: Covid-19 has the potential to be the worst pandemic since the so-called Spanish flu. With intelligent and coordinated intervention by government based on the best science, it can be handled, but there is no way to avoid serious economic and social disruption.

What about "opening up"? This is very tricky since the full range of the effects of the virus, including long-range effects, are still poorly known. But there are some things that can be done. Testing and tracing should be concentrated where there are hot spots and higher concentrations of people who are vulnerable, such as in communities of color, for older people, for those with health problems, for workers in essential jobs, and for those in detention. Unfortunately, the US has been very sluggish in ramping up testing, which is key to opening up. Transmission of the virus outdoors appears to be minimal, so parks and other recreational areas might be opened but closely monitored. With sufficient protections a lot of businesses should be able to open. But remember. The real danger of the virus is its ability to overwhelm the medical response, which would also put people with other life-threatening conditions at greater risk. This already appears to be occurring to some extent.