A UF Health epidemiologist explains what it means to flatten the virus curve and its local impact.
The nation is approaching nearly two months of shutdowns and social distancing to address the threat of COVID-19, which has altered virtually all aspects of life. A main goal is to “flatten the curve” of the coronavirus spread.
But what does that mean for Jacksonville and surrounding areas? And, more importantly, have these efforts helped reduce the spread of COVID-19 and prevent deaths?
What is the curve?
The curve is created by the initiation, spread and eventual regression of a virus within a defined population across a specified time period. It’s usually represented visually by a line graph that plots the number of new positive cases diagnosed each day.
The first part of the curve moving upward represents the start of the spread. The top of the curve indicates the peak with the highest number of new cases on a specific day, and the downward slope is the reduction of new confirmed cases as the spread slows due to people building immunity. This is considered the “natural” curve for viral spread throughout a population because it illustrates what happens if no measures are taken to alter the spread.
While there will always be a natural curve when a virus spreads, what can be controlled is the height, or peak, of the curve and how rapidly the peak is reached. Viruses, such as the one that causes COVID-19, spread easily and move quickly though a population over a relatively short period of time. Therefore, the natural curve looks like a steep mountain with a high peak.
Flattening the curve means taking actions that effectively reduce the ability of a virus to spread. As such, the overall number of people who become infected and the pace at which they become infected is lowered.
Looking at it locally
The natural curve is different for each geographic region, since it takes the size and density of the population into account. The way the curve looks in Jacksonville will be different than the curve in a city with a larger population that is more densely populated or a smaller city that is more spread out.
According to Alexander Parker, PhD, an epidemiologist and senior associate dean for research at the University of Florida College of Medicine – Jacksonville, examining the curve at a county or city level is more relevant than at a state or national level.
Based on 2018 census estimates, Jacksonville has a population of just under 1 million, but is also one of the country’s largest cities by area. When battling an infectious disease that is spread by close contact, this proves to be a positive, as the virus will move more slowly from person to person than it would in more densely populated cities.
However, Parker warns that although it moves differently in Jacksonville, an uncontrolled high peak would still be devastating and put more strain on the local health care system.
Why is flattening the curve so important?
Flattening Jacksonville’s curve is vital to protecting the community and avoiding overwhelming the health care system.
“Right now, we have the number of health care institutions in our city that are needed to provide high-quality care for our population,” Parker said. “The issue arises when there is a disturbance in our ‘normal’ situation that increases the demand for medical care. Then the system becomes stressed. If not kept in check, it can become overwhelmed and incapable of handling the increased need.”
The added strain brings the risk of a rapid increase in demand for medical services and, ultimately, the exhaustion of hospital resources and space. It also results in less medical staff, who may become sick after being exposed to the virus. This not only affects COVID-19 patients, but also impacts overall patient throughput.
“If there isn’t enough staff, resources or space to care for patients, then we dramatically increase the risk that people will die unnecessarily,” Parker said. “And I don’t just mean people with COVID-19, who have a higher risk of death due to preexisting conditions. People with other life-threatening conditions who would normally be taken care of could have a very different outcome. This affects everyone.”
What measures can be taken?
People around the world are already taking precautions and working toward flattening the curve, but some of the important actions to continue taking include washing hands before meals, after using the restroom and after touching public surfaces, avoiding touching your face, wiping down surfaces in your home regularly and social distancing as much as possible.
Parker says the latter action is a top influencer on the curve. Avoiding in-person interactions hampers the ability of the virus to spread.
In public, wearing a face covering, such as a homemade mask or bandana, is also an effective way to reduce the spread, especially when so many may be asymptomatic. By contrast, wearing gloves will not slow the spread if worn everywhere. The virus lives on gloves the same way it lives on hands, so it’s best to wash your hands as much as possible or use hand sanitizer.
Beating the virus
Parker says beating the virus involves a combination of factors, including having effective vaccines and treatments, as well as tests that provide faster results. That allows health care professionals to identify and isolate the infected quickly. It also includes developing a way to identify those who are already immune and using this as part of a strategy to safely reintegrate them into society.
Society opening back up too early could also have devastating results. As of early May, several states, including Florida, are implementing plans to phase back into normal life. Parker recommends using extreme caution during this time and continuing to practice social distancing as much as possible. Returning too abruptly could result in a second wave and, ultimately, a second curve.
Despite the bleak outlook, Parker is confident the goal to flatten the curve in Jacksonville will be achieved with the current measures in place.
“When these worst-case scenarios don’t happen, it’s because of our efforts the past couple of months to flatten the curve,” Parker said. “Interestingly, our goal is to make it look like we didn’t need to do it at all.”
Senior Associate Dean for Research