This interactive map shows the risk of COVID contagion across the country. But there are things the tool can’t predict.
As coronavirus infections continue to surge in nearly every state, there is a growing concern about the increased risk of contracting the illness that so far has impacted more than 11.1 million Americans and taken 247,000 lives across the nation.
And with the holidays just around the corner, it is vitally important to be informed of the risk of every gathering, no matter the size of the event or where it takes place. This is especially true if it includes visitors traveling from other states.
For this reason, the Centers for Disease Control and Prevention (CDC) posts on its website considerations for events and gatherings, from highest-risk activities (large in-person gatherings where it is difficult to remain spaced at least 6 feet apart and attendees travel from outside the local area) to lower risk (virtual-only activities, events, and gatherings), and others in between.
An Interactive Tool
Researchers at the Georgia Institute of Technology have developed an interactive map that shows the risk for gatherings of different sizes in each county across the US. This is based on at least one of the people attending being infected with coronavirus.
The COVID-19 Event Risk Assessment Planning Tool is a collaborative project led by professors Joshua Weitz and Clio Andris at the Georgia Institute of Technology, along with researchers at the Applied Bioinformatics Laboratory and Stanford University. (A description of the method and analyses are available at Nature Human Behaviour.)
How to Use the Map
The map is updated daily with the latest information on how many cases have been tallied in every county across the US as a way to visualize the risk associated with gatherings. Therefore, a 12% chance of encountering an infected person on Tuesday could change by Saturday.
By moving the slider on the left of the map to the number of people they expect to attend the event (from 10 to 5,000), then hovering the cursor over the outline of the county where the event will take place, users can see the map change color based on the risk of attending an event with someone actively infected with Covid-19, according to the study, which was published in the peer reviewed journal Nature Human Behavior. For example, light yellow areas have risk levels below 1% while dark red regions have risk levels above 99%.
The map combines documented coronavirus cases at the county level and data from antibody test results, which reveal more infections than reported by state health departments. Also, because not all cases will be caught by tests, the tool also assumes that the actual number of coronavirus cases is up to 10 times higher than what’s in the official reports.
What the Tool Can’t Tell You
However, there are things the tool can’t predict. The Georgia Tech tool doesn’t tell you your risk of actually contracting the virus at an event. That’s because a person’s risk depends on many variables: Is it held outdoors or indoors? Is there proper distancing? What’s the ventilation? Are people wearing masks? Are they touching objects? The map also isn’t able to adjust for people’s behaviors, which may affect the risk of potential virus transmission. In other words, the tool can’t tell you whether an 11% chance of sharing space with someone capable of infecting you is too high to make your attendance worthwhile.
Hot Zones Light Up
An analysis published by Miami Herald revealed that Midwestern states have the most red-colored counties regardless of the size of the gathering. Gatherings with 25 people cause the map to show more red-colored counties,”with states like Wyoming, Texas, Wisconsin, Illinois, and Minnesota seeing major spikes in risk levels,” according to the analysis.
The reason for this is that large indoor gatherings are cesspools for viral spread and have been linked to large outbreaks of COVID-19 in particular.
In fact, a recent study by Stanford University found that reducing indoor maximum capacity in spaces such as hotels, cafes, religious centers, gyms, and restaurants to 20% could cut down new infections by about 80%.
Be Careful, Even in Small Gatherings
Researchers warn of the need to protect yourself and others no matter the size of the gathering.
“Precisely because of under-testing and the risk of exposure and infection, these risk calculations provide further support for the ongoing need for social distancing and protective measures. Such precautions are still needed even in small events, given the large number of circulating cases,” they wrote on their website.
“You can reduce the risk that one case becomes many by wearing a mask, distancing, and gathering outdoors in smaller groups,” they recommend.
Don’t Rely on Just One Tool
Several experts, as well as Emily Landon, chief infectious disease epidemiologist at University of Chicago Medicine, told The Washington Post people should be cautious when using risk assessment tools and not rely on a single source, which “could create a false sense of security as cases continue to surge.”
People can find information about the spread of the virus in their communities and nationwide through online data dashboards maintained by states, the Centers for Disease Control and Prevention, universities such as Johns Hopkins and national media outlets, including The Washington Post. Also, professors at Brown University released an app (MyCovidRisk) this fall that estimates a person’s chances of getting the virus from specific activities and offers suggestions for how they can reduce risk.
“It’s time for us to be looking out for each other and really be tightening up our own behaviors and interactions so that we can get through winter with fewer cases and fewer deaths,” Brian Garibaldi, medical director of the Biocontainment Unit at Johns Hopkins, told The Washington Post.