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7 data visualizations that explain COVID-19

Interactive maps, infection projections and your own PCR data illustrate how serious the COVID-19 pandemic is in your response area

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Throughout the last two months, Seattle and King County have been on the front lines of the COVID-19 pandemic in the United States. The first COVID-19 case within our borders was confirmed in Snohomish County, Washington on Jan. 21, 2020. The first reported death happened nearly six weeks later at a hospital 15 miles from downtown Seattle. For a month and a half, the virus had spread unabated in our community. And now we are paying the price.

In the time since, the humanity of every individual across the healthcare spectrum has been highlighted. Those in administrative roles have worked non-stop since Friday, Feb. 28, 2020. Those in clinical and supportive roles have taken extra shifts in high-risk environments to make sure all patients get the care they deserve. We have relied on a wonderful matrix made up of healthcare, government and private industry to better understand and diminish the impact this virus is having on our community.

This is not the flu. COVID-19 is a different kind of deadly. It camouflages in the healthy as nothing more than a bad cough, but for the elderly and immunocompromised, it’s the source of mass graves in Iran and overflowing obituaries in Italian newspapers.

Surprisingly, one the most important tools we’ve relied on is data visualization. Although paragraphs filled with numbers can tell a story, a picture is worth 1,000 words, and a gif 10 times more than that. What follows is a list of 7 data visualizations that can help you tell the story of just how serious this pandemic is.

1. Johns Hopkins Coronavirus Resource Center

The Center for Systems Science Engineering at Johns Hopkins University has created what is likely the most famous map of the global COVID-19 case count. It’s interactive and users can focus in on single countries and regions.

2. New York Times: Tracking Every Coronavirus Case in the US

Once COVID-19 started taking lives within the United States, the New York Times increased its coverage drastically. This map, with each circle representing a county, provides the most up-to-date data on reported cases. It is likely more up to date than the CDC website as it is only updating case counts on weekdays.



3. Our World in Data: Trajectories since the 100th confirmed case

This visual is probably one of the most powerful on the internet because it compares the growth rate of individual countries after their 100th confirmed case. Countries that are “behind the curve” are reporting a doubling of the number of cases every 2 to 3 days. These are countries that have little control over the growth of the COVID-19 epidemic within their borders and include Iran, Italy, France, and the United States.

Countries like Singapore and Japan are only seeing their confirmed case count double every 5 to 10 days. This is because these countries enacted strict public health-centric policies after the first reports of COVID-19 within their borders.

Hopefully, as some of the policies being enacted across the United States take effect, we can start to see whether or not we are flattening our own curve.

4. Reuters: The Korean Clusters

Although South Korea was slow to accept that they had an epidemic, since then they have done an amazing job of testing. Of the 51 million people that live there, they’ve tested nearly 250,000, or 3,600 tests per million. This is compared to 5 tests per million happening in the United States.

This is important because it will help researchers better understand two things: how quickly COVID-19 spreads and how deadly it is. While countries like Italy and the United States only test the sickest patients, making the mortality rate seem artificially high, South Korea’s willingness and capacity to test anyone allows identification of those that are positive, but have less significant symptoms, giving us a more realistic understanding of how COVID-19 presents across an entire population.

As far as mapping the significant impact one infected person can have on an epidemic, Reuters has a fantastic visualization of “Patient 31.” It’s estimated that she had contact with over 1,000 people, many members of the Shincheonji Church of Jesus, one of the epicenters of South Korea’s outbreak.



5. New York Times: The Workers Who Face the Greatest Coronavirus Risk

A recently created interactive story by the New York Times highlights the various workforce categories that likely face the greatest risk of contracting COVID-19 based on the interaction between their exposure to diseases and their physical proximity to others.

Top among the workforce? Paramedics, police officers and firefighters.



6. Your own data

Your agency’s data can tell you where your community stands on the epidemiological curve. It’s mid-March, everyone should be seeing a decrease in “flu-like” illnesses. In all likelihood, you’re actually seeing an increase. But is that increase 2 fold, 4 fold, or 20 fold your normal numbers? Only your data can tell you.

Importantly, the hard work has already been done. ESO has created an Ad Hoc report for tracking patients with a “COVID-19” Impression. They’ve also shared a copy of the logic Seattle Medic One is using to track patients with the known signs and symptoms of COVID-19. Similarly, FirstWatch has created a trigger tool for tracking these patients, and I would expect Image Trend to have their own version as well.


Photo/ESO & FirstWatch

7. Washington Post: How to “Flatten the Curve”

“Flatting the curve” has become the rallying cry for many that recognize their role in dampening the effects of COVID-19. The sad reality is that no healthcare system, anywhere in the world, has the capacity to handle an influx of critically ill patients that an unmitigated outbreak of COVID-19 brings. In order to maintain some capacity within the healthcare system, we must elongate the time it takes for the disease to move from one patient to the next.

This Washington Post article does a great job of walking the reader through four scenarios of varying extremes that demonstrate what the COVID-19 case volume would look like over time. The closer we are to extensive distancing, the more people survive.



In Seattle, a team of experts led by The Institute for Disease Modeling have calculated what impact different levels of social distancing would have on the estimated infections and subsequent deaths based on current case counts. If our community continues on like nothing has happened, we can expect to see 25,000 infections by April 7, and from those, 400 subsequent deaths. But if we reduce our social interactions by 75%, the Seattle area can expect only an additional 1,700 infections, and from those 30 subsequent deaths.

The difference between 30 deaths and 400 is not only significant because it’s a 13-fold difference in funerals, but also because it means we have to drastically cut down on social interactions for the foreseeable future. While it’s hard, if we remind ourselves the significance of our actions and rely on technology to fill the gap, it is possible to flatten the curve.

Additional COVID-19 response resources

Learn more about how EMS is responding to the COVID-19 pandemic with these resources:

Catherine R. Counts, PHD, MHA, is a health services researcher with Seattle Medic One in the Division of Emergency Medicine at the University of Washington School of Medicine. She received both her PhD and MHA from Tulane University School of Public Health and Tropical Medicine.

Dr. Counts has research interests in domestic healthcare policy, quality, patient safety, organizational theory and culture, and pre-hospital emergency medicine. She is a member of the National Association of EMS Physicians and AcademyHealth. In her free time she trains Bruno, her USAR canine.

Connect with her on Twitter, Facebook, or her website, or reach out via email at