This work was written by Mark Joslyn and Louis Joslyn . Louis is a PhD candidate in computational medicine and bioinformatics at the University of Michigan.
Over the past two months, Americans have relied on the recommendations of scientists and other respected professionals. Public health officials recommended social distancing and government lockdowns as a means to arrest the spread of COVID-19. They also pushed for widespread testing of the population, wearing masks, and proper hygiene.
Americans generally followed the advice of public health officials, with some exceptions.
But today, political parties – and by extension, Americans – are divided on the next steps forward. Anxious about potential mass spread of disease, Democrat leaders insist on deliberate steps toward reopening the economy. To Democrats, the path forward should be informed by scientific facts and with an understanding that the virus may rebound.
Eager to forge ahead, Republican leaders reference science as well, pointing to the models, country-level statistics and case studies that demonstrate a brighter future.
Both sides are criticized for twisting science to suite a political agenda.
Partisan politics now threatens to ensnare the science of Covid-19.
A Measure of Disease Severity
When tracking the spread and severity of disease, epidemiologists use, among many other models and statistics, a measure called the case fatality rate. The case fatality rate is the proportion of deaths from disease compared to total number of cases within a specified time period:
As of March 6, the World Health Organization stated that the case fatality rate was around 3%. This measure is known to range widely depending on regional differences throughout the world (such as healthcare infrastructure), patient characteristics (such as age), and testing strategies (which can impact the total number of cases).
In fact, we now know that people can be infected with the novel coronavirus but experience mild or no symptoms – these individuals are deemed ‘asymptomatic’. In Iceland, for example, which tested widely and did not limit testing to people with symptoms, 50% of cases tested positive – but showed no symptoms. The CDC’s director, Dr. Robert Redfield, indicated that as many as 25% that are infected remain asymptomatic.
Additionally, a recent Lancet article showed that testing revealed approximately 20-25% of Stockholm County, Sweden residents have been infected and 98-99% were unaware of having had the infection. They either exhibited no symptoms, or symptoms were not severe enough to seek medical assistance.
Scientists and public health officials are, of course, aware of the shortcomings of an observed case fatality rate based solely on confirmed cases. As early as February and March, scientists warned that we may be over-estimating or under-estimating the case fatality rate drastically, due to our testing strategies and case definitions.
However, these warnings have not stopped each political party from distorting this particular scientific measure for their own gain.
How Democrats Distort Science
On cable news outlets, especially Democratic strongholds – CNN & MSNBC, the number of coronavirus deaths and cases are presented daily.[i]
Much like developments in the financial markets, the numbers are updated and displayed alongside the news anchor. The deliberate placement seems cold but does capture the eye. The numbers serve as a reminder of the grim reality of the pandemic and perhaps symbolize the Trump administration’s failure.
Deaths are displayed first, and the number of cases just below. This encourages viewers to divide one by the other, thereby calculating a potentially high observed case fatality rate (6% as of May 13, when viewing CNN). However, this reasonable conclusion may not be scientifically accurate in regards to the true severity of infection as it explicitly ignores the important assumptions and drawbacks intrinsic to the calculation of the true case fatality rate that were mentioned in the previous section.
How Republicans Distort Science
As we have stated, scientists recognize the case fatality rate does not reflect the actual risk of death for a Covid-19 infected person. It is a useful statistic, but based on confirmed not total cases.
Yet scientists can and have estimated the actual cases. They estimate the actual number of cases to be substantially greater than confirmed cases. This portends a significant reduction in the likelihood of death after infection – the denominator grows much larger and consequently the derived percentage smaller. Republicans hand-pick this as evidence to re-open the economy, because the death rate appears much smaller than we previous anticipated.
Democrat and Republican assessment of asymptomatic individuals
The discovery of a significant number of asymptomatic people validates both Democrats and Republicans observations.
For Republicans, the fact that thousands more are infected but remain undetected means the case fatality rate overestimates the risk of death – by quite a lot. This evidence supports Republican’s enthusiasm for reopening and pushing ahead confidently.
For Democrats, the exact same discoveries justify their more restrained approach. After all, millions of infected people moving about freely among vulnerable populations – showing no signs of illness – represent a genuine health threat to thousands, if not millions of vulnerable people. To democrats, this fact demands increased vigilance, not easing of restrictions. The discovery of asymptomatic individuals is a call for continued social distancing, the use of face masks, and a measured re-opening of the economy.
Partisan politics re-emerges
Initially, facing an unknown pandemic, both parties adopted proven scientific methods. But after a time, party politics have reemerged. Scientific facts, formulas, and models that validated each side’s divergent partisan motivations have gained traction.
Much remains unknown about COVID-19. Until a vaccine or effective treatment emerges, we can be certain that each side will only mine the ‘science’ that validates their views.
[i] On occasion Fox News, a Republican favorite, displays the numbers. The display, and irregular presentation, highlights partisan differences with CNN and MSNBC.