Liz Specht writes:

Much of the current discourse on — and dismissal of — the Covid-19 outbreak focuses on comparisons of the total case load and total deaths with those caused by seasonal influenza. But these comparisons can be deceiving, especially in the early stages of an exponential curve as a novel virus tears through an immunologically naïve population.

Perhaps more important is the disproportionate number of severe Covid-19 cases, many requiring hospitalization or weekslong ICU stays. What does an avalanche of uncharacteristically severe respiratory viral illness cases mean for our health care system? How much excess capacity currently exists, and how quickly could Covid-19 cases saturate and overwhelm the number of available hospital beds, face masks, and other resources?

This threat to the health care system as a whole poses the greatest challenge.

As I initially described in a Twitter thread, simple mathematics can derive rough estimates for how this might play out.

I think most people aren’t aware of the risk of systemic healthcare failure due to #COVID19 because they simply haven’t run the numbers yet. Let’s talk math. 1/n

— Liz Specht (@LizSpecht) March 7, 2020

This exercise can inform our level of urgency and equip us to anticipate non-obvious, second-order effects, some of which can be mitigated with proper preparation.

As of March 8, about 500 cases of Covid-19 had been diagnosed in the U.S. Given the substantial underdiagnosis at present due to limitations in testing for the coronavirus, let’s say there are 2,000 current cases, a conservative starting bet.

We can expect a doubling of cases every six days, according to several epidemiological studies. Confirmed cases may appear to rise faster (or slower) in the short term as diagnostic capabilities are ramped up (or not), but this is how fast we can expect actual new cases to rise in the absence of substantial mitigation measures.

That means we are looking at about 1 million U.S. cases by the end of April; 2 million by May 7; 4 million by May 13; and so on.

As the health care system becomes saturated with cases, it will become increasingly difficult to detect, track, and contain new transmission chains. In the absence of extreme interventions like those implemented in China, this trend likely won’t slow significantly until hitting at least 1% of the population, or about 3.3 million Americans. [Continue reading…]