What does ‘flatten the curve’ mean?

By Aliyya Sawadjaan
Features Writer, The Philippine STAR

Authorities all over the globe are doing their best to curb the number of positive coronavirus disease 2019 (COVID-19) cases and deaths. Quarantine and lockdown measures have been implemented, with the goal of “flattening the curve.” But what does it really mean?

This curve is what researchers refer to as the projected number of people who will contract COVID-19 over a period of time, a theoretical number used to model the virus’ spread.

In the graph, there are two curves — a steep one and a flatter one. The steep curve shows the spread of the virus and the infection rate at its most escalated state. The steep rise of the infection curve also has a steep fall — meaning, after the virus infects the majority of the people, the cases will begin to drop exponentially as well.

The flatter curve, on the other hand, assumes the same number of people getting infected but over a longer period of time or at a slower rate. The slower infection rate means a less stressed health-care system — with enough medical frontliners to attend to patients and adequate medical equipment and facilities.

UNDERSTANDING THE SPANISH FLU PANDEMIC

Experts keep using the Spanish Flu to show how to flatten the curve.

The H1N1 virus, which originated from birds, caused a global pandemic in the late 1910s. It was first identified in the US in the spring of 1918, but was dubbed as Spanish Flu because during the First World War, Spain was a neutral party and therefore could report on the severity of the pandemic.

It was the world’s last big pandemic caused by a respiratory-based virus and the third deadliest in the last millennium with 50 million casualties.

Since the world was in the middle of a war, medical facilities were stretched as hospitals had to treat the injured and attend to the casualties of war. Add to this, many doctors were also on the frontline. Another factor why the virus spread widely was because of poor hygiene, as people lived in difficult and crowded conditions.

There was no vaccine available, which is also the case for the COVID-19 now. There were no antibiotics to treat secondary infections. The only non-pharmaceutical responses available to control the spread of the flu were isolation, quarantine, limited public gatherings, and use of disinfectants.

DO THESE MEASURES WORK?

Yes. Studies have shown that social distancing (or physical distancing) is crucial to prevent viruses. Minimizing close contact with others reduces the chances of catching the virus and spreading it to the community.

In the Philippines, the Enhanced Community Quarantine (ECQ) has helped contain the spread of COVID-19, according to Dr. Edsel Maurice Salvana, director of the Institute of Molecular Biology and Biotechnology at the University of the Philippines – National Institutes of Health (UP-NIH).
In a Facebook post last April 18, Salvana said that with a little over 200 cases of COVID-19 daily, “there is little doubt the ECQ has succeeded in slowing down the spread of COVID-19 in the Philippines.”

“Even without ‘mass testing,’ the fact that we are measuring the severe/critical population on a daily basis gives us a good picture of the shape of the curve.”

Based on the data from the Department of Health (DOH), the number of cases had “gone from a three-day doubling time from March 28 to 31 (from 1,000 to 2,000, the tail end of the number of cases prior to ECQ since incubation time was up to 14 days) to a doubling time of 14 days (from 3,000 to 6,000 between April 4 and 18).”

But he also pointed out that “due to the extreme cost to the economy, the ECQ is not a sustainable intervention.” Nevertheless, it has bought time for health-care facilities to prepare and prevent an overwhelming surge of patients to the hospitals.

The potential for cases to surge is always there, but this will not be seen within two weeks after quarantine is lifted. This is because the first two weeks will be made up of cases acquired during the lockdown as incubation period is up to 14 days.

“This may lull us into a false sense of security if it stays low until there has been real harm done. Therefore, if ECQ is going to be modified, it needs to be done slowly and allow the data to catch up, so we know what is truly going on,” he suggested.