The summer of lost hopes
At one moment there was hope that summertime will naturally suppress the spread of COVID-19. This hope is now gone as uncertainty sets in.
In the beginning of June, the COVID-19 trends in the US looked quite promising. The incidence rate (number of cases per 100,000 people) was about 10 or less, with the pandemic hotspots in secure downward trends. The incidence doubling time was in almost every state over one month, mostly two or more months, which was a slow trend that was the goal of “curve flattening”. The summer was coming just at the right time, when viral respiratory illnesses typically get subdued. The situation was perfect for setting up long term public health policies to combat COVID-19 when fall arrives and prepare the health system for the inevitable increase of COVID-19 cases by the end of the year. Unfortunately, the situation quickly escalated thanks to political struggles and ignored warnings that the virus is on the loose over most of the country.
The economic and political pressures have been pushing toward faster exits from state lockdowns and restrictions on mobility. At the same time, a lack of consensus on public health measures, such as on wearing masks or the severity of the disease, eroded the efforts to use this precious time to promote a “new normal”, i.e. public health measures that would prevent a rapid spread of the virus. The states started to move to reopening as fast as possible. We can see the exact moment of when a state reopened in the data on restaurant reservations registered by the OpenTable network.
Figure 1 shows the incidence rate by state as a function of restaurant reopening. Three remarkable features stand out. First is how in July the incidence rate jumped dramatically in states that reopened early, with Florida and Arizona leading the pack. At the same time states that opened later maintain a low incidence rate. The second feature is the political divide: the states that opened early are almost all led by Republican governors. The two exceptions, Maryland and Massachusetts, have Republican governors who openly criticize the president and do not follow his political lead. The third feature is the opposite situation in April, when the Republican “early opening” states were in a good shape with COVID-19, while the “later opening” states were struggling to suppress the spread of the virus. The animation in Figure 2 illustrates these trends in time.
In mid-June the situation started to deteriorate quickly as the number of cases started to rise. The key problem here was that the main guideline for reopening was a downward trend in cases, which has been largely ignored. If we look at the timeline of the number of infected people in the US (Figure 3) we can see that, when New York and New Jersey are excluded, the US had a constant number of cases. This means the virus was in a free circulation, spreading like wildfire.
When these pandemic trends are shown on the map some misleading impressions can be inferred. An ordinary map does not illustrate how many people are affected as lots of people live in densely populated urban areas. Therefore, we map the trends on a cartogram — an illustration where the size of a US county on the map is proportional to the fraction of its population in the total US population. This way we can get a correct impression on how severe the pandemic is. Figure 4 shows such a map with colors depicting the doubling time of COVID-19 incidence rate calculated on the data for the two weeks prior to July 14, 2020. It is obvious from such a map how devastating it is to have a community spreading of the disease in large urban areas. Notice also how the initial hotspot in the larger New York metropolitan area is now the region with the smallest incidence rate. An animated version in Figure 5 shows an evolution of this situation over time, from a scary rise of COVID-19 cases in April to intermediate calmness by the end of May and start of June, and finally the most recent rise in cases (for an interactive version see Figure 6). The animation also helps to visually connect the shapes in an ordinary map with the cartogram.
The increase in death rate comes in the wake of rising COVID-19 cases. Figure 3 shows that August will start with over 150,000 deaths in total. The death rate is somewhat slower than the incidence rate, but this is due to there being more cases among younger population and (maybe) the summer weather. The problem is that hospitals are starting to feel the approaching tsunami of cases in need of hospitalization. The hope, now ruined, was that such a scenario could be postponed to the fall, when the respiratory illnesses typically start to rise again. Instead, the US is already under a full-blown virus attack while the options to stop it are not only limited, but also deeply politicized.
Under such conditions only total lockdowns can stop the virus, but this is not an option that anyone is willing to take any more. Instead, limited measures will be implemented, such as limits on gatherings or business activities that cannot avoid a close human contact. This means that the economy will suffer dramatically because of such measures and suppressed personal spending driven by the fear of long-term economic disruption. Until now epidemiologists were dictating the measures and economists had to adjust. Now economists will dictate the rules of the game and epidemiologists must figure out how to fight the pandemic under the given limitations. The outcome could be even more deaths and maybe political instabilities. Not only in the US, but also globally as the virus is taking its death toll almost everywhere.