Coronavirus Disease 2019 (COVID-19):  Flattening the Curve

Coverage of the coronavirus disease 2019 (COVID-19) seems to be never ending these days.  Television networks, radio, and internet media sites are all scrambling to provide the latest updates on the virus outbreak.  If you have been listening to these sources, chances are you have likely heard the phrase “flattening the curve” and wondered what it means.

Epidemiologists refer to a “flattening or bending of the curve” when discussing methods to prevent the sudden outbreak of new cases of COVID-19.  The goal of flattening the curve is to help people avoid severe illness, keep the number of infected down, reduce the numbers of deaths, and avoid overloading the already stressed health and medical supply infrastructures.

COVID-19 overview

COVID-19 first appeared in December 2019 in Wuhan, China.  In a matter of just a few months, the virus has spread to over 185 countries, infected over 400,000 people, and resulted in over 16,000 deaths.  Cases of COVID-19 started appearing in the United States in late January 2020 and to date, has infected over 40,000 people.  Characterized by a fever, cough, tiredness, aches, and shortness of breath, symptoms of COVID-19 generally present within two to 14 days following exposure.  Some patients will show no signs of illness, but symptoms generally range from mild to severe with the elderly and those with pre-existing medical conditions (asthma, diabetes, heart disease) being at the highest risk for developing significant illness.

Currently, there are no medications to treat COVID-19 that have been approved by the United States Food and Drug Administration (FDA).  As such, the primary course of action is to treat symptoms of the virus through over the counter medications, adequate rest, taking in fluids, and avoiding contact with infected people or contaminated surfaces.  Since it appears that the virus is primarily transmitted through person to person contact and respiratory droplets (from a cough or sneeze), practicing social distancing and isolating yourself from others, are the recommended prevention techniques.  Many state governments have mandated stay-at-home orders, schools have shut down, and businesses are either scaling back hours of operations or closing all together.  Public events and gatherings have also been cancelled or postponed in order to curtail the spread of the virus.

What is meant by the “curve”?

              Researchers use the term “curve” when referring to the number of people projected to contract a virus, in this case COVID-19, over a period of time.  While this is an estimate, rather than a definitively known number, epidemiologists can use the theoretical model to gauge how fast the virus will spread.  Depending on the infection rate of a virus, the curve can take on several different shapes.  For viruses that spread exponentially (when the number of cases keeps doubling at a consistent rate), the curve can be steep.  The steeper the curve, the faster health care systems get overloaded and supplies run out.  Perhaps the only good thing about an exponential rate of spread, is that the steep rise in infection means that the number of cases will fall exponentially once everyone that can be infected has been infected.  On the other hand, if the number of patients that are infected remains constant but happens over a longer timeframe, the curve is flatter and will result in less stress being placed on both the health care system and availability of supplies.

How to flatten the curve

According to health experts at the Mayo Clinic, the best method for flattening the curve is for people to implement social distancing practices. Because the primary vehicle for transmitting the virus is contact with people that are sick, isolating yourself from others can prevent large spikes in the number of cases. To paraphrase Dr. Clayton Cowl, the chair of the Mayo Clinic’s Division of Preventive, Occupational and Aerospace Medicine, "In epidemiology, when we look at an illness like COVID-19, we see an initial flattening. At a certain point, it reaches a time when we see a spike in the number of cases and the number of fatalities. The whole idea of social isolation is to try to bend that curve. In other words, to prevent that big spike." Taking a lesson from prior virus outbreaks, such as the 1918 Spanish flu epidemic, has shown that keeping people separated and not in close quarters, can make a huge difference in minimizing the spread.

Why is flattening the curve important and how do we do it?

One of the scariest aspects of COVID-19 is how rapidly the illness can spread.  It took less than a month for the number of confirmed cases of COVID-19 to double worldwide.  On February 20, there were roughly 75,000 cases globally but by March 15, the number had jumped to over 153,000.  While the global infection rate is staggering, it has spread especially fast in the hardest-hit communities.  Italy, whose COVID-19 outbreak is second only to China, reported a doubling in the number of confirmed cases in only four days (March 11 to March 15) and with a rate of about 7%, has a mortality rate that is roughly double the worldwide average.  Some hospitals in Italy are already filled to capacity, have been forced to close emergency room doors to new patients, request emergency medical equipment supplies, and hire hundreds of additional doctors.

It is believed that in the coming weeks and months, the number of patients infected with COVID-19 will continue to grow and be in the millions.  As the Italian outbreak has shown, the rate of infection is perhaps the greatest contributor in ensuring adequate supplies of tests, hospital beds, doctors, and resources needed to treat those infected.  Therefore, “flattening the curve”, to slow the spread of the virus so that fewer patients need to get treatment at any given point, is vital to ensure adequate resources are available to treat the illness.

With no approved vaccine or medication available to treat COVID-19, the best method for flattening the curve is through collective, preventative action.  Frequent hand washing and the practice of social distancing (avoidance and isolation), should be implemented immediately.  Working from home, avoiding any public places or events, and self-quarantining yourself if you feel sick, are also highly advised methods for reducing potential spread of COVID-19.