To help businesses better understand the growth of Covid-19 infections and assess when to begin assuming more standard operations, RSM has developed a fitted curve projection model.
The number of coronavirus cases in the United States has continued to surge, moving past 336,000 this past weekend. There have been more than 9,600 reported deaths from Covid-19 infections, for a 2.8% mortality rate.
A forward-looking metric that assesses the impact of the virus.
It leaves businesses trying to assess the risk of further contagion, and how to proceed. We have created this model of a fitted curve to provide both internal and external clients with a data-based heuristic to use when discussing and planning a return to work.
This forward-looking model we think will capture curve dynamics in near real time and provide an informative and useful metric around which to begin planning on a return to full production and provision of services.
The model, though, shows that any thought of easing the policy of self-distancing or issuing return-to-work edicts by the federal and state governments or firms at this time is premature. Should the public not adopt safe practices and remain quarantined, and should business fail to remain shuttered, the number of cases could breach 400,000 within days.
Early on, as the figure below illustrates, the spread of the virus rapidly increased, doubling from eight cases as of February 1 to 15 cases 10 days later. The virus then spread from 15 cases to 100 cases in just three weeks. A week later, the virus had spread to 1,000 people, growing at an identifiable exponential rate.
Not only was the spread growing exponentially, but the basic parameter of that spread was accelerating as well. In the basic exponential model, as discussed in Science magazine, “the number of new infections triggered by each case, also known as the basic reproductive number, or R0,” was identified as growing over time from 2 in the early days to more than 3.
This means that in the earliest days of the outbreak, each person who was infected would infect two others each week, who would infect two others, and so on. That has now changed to each person who is infected will infect three others each week, and so on. Compare that to the 1.3 value of R0 estimated for the flu season each year. Thus, any claims that the Covid-19 virus is like the flu are categorically untrue and not in the public interest.
The mortality rate is also rising, with deaths from the coronavirus in the United States increasing from about 1.5% of infected persons to 2.8% during the latest week. As the figure below illustrates, more than 9,600 people have died, with deaths averaging 1,000 per day in the latest week.
Other countries are showing similar exponential growth of the virus. England reluctantly closed down all normal life on March 23, but not before 500 deaths and a mortality rate of 4.8%. Since then, cumulative cases have grown to 48,000, with 4,300 deaths as of the first weekend in April and a dreadful mortality rate growing to more than 10%.
Can the U.S. stop the spread? We can only look to South Korea, where the spread of the virus has moved from an exponential increase in Covid-19 cases to a deceleration.
Because of its experience with MERS outbreak in 2015, South Korean society allowed legislation that “gave the government authority to collect mobile phone, credit card and other data from those who test positive to reconstruct their recent whereabouts. That information, stripped of personal identifiers, is shared on social media apps that allow others to determine whether they may have crossed paths with an infected person,” according to Science magazine.
As the figure below indicates, the spread of the virus changed from an exponential increase to what resembles a log function on or about March 4. Though the cases are still increasing, it is no longer the rapid acceleration shown before the inflection point.
So what does South Korea’s experience suggest for U.S. business and policymakers? A national program of testing, isolation and the backtracking of known contacts appears to be the only known method for slowing the spread of Covid-19.
These steps must be in place before reopening the local economy:
- A consistent decrease in the number of cases.
- The ability to test the entire population, isolate infected persons and trace the source of the infection.
- A sufficient amount of health-care apparatus and staff is available should the virus re-emerge.
- An effective therapy and vaccine is available to the entire population.
- The willingness to invest in research to prepare for the next virus.
While U.S. society is not likely to accept the sharing of personal information, that leaves the combination of personal responsibility and the quick shutdown of business and public and private gatherings as the only way to prevent an infected person from infecting others. If not, the results are likely to be catastrophic, in both the short and long-term.
While the current environment of stay-at-home mandates is challenging for businesses and individuals, it is helping to contain the spread of the virus and flatten the curve. While painful to the economy in the short-term, it will enable businesses to more quickly return to standard operations than if no action were taken.
For more information on how the coronavirus is affecting midsize businesses, please visit the RSM Coronavirus Resource Center.