How dangerous is it to be in a crowd in SC? Map helps you calculate the risk
A new tool can help determine how risky it is to be in a crowd in South Carolina during the pandemic.
The tool, created by the Georgia Institute of Technology and Applied Bioinformatics Laboratory, calculates the chances of coronavirus exposure at different gatherings in South Carolina, statewide and in each county, based on crowd size and the circumstances of the pandemic.
Users input the crowd size, and the model shows the chances that at least one person there has the virus.
It updates regularly based on the most recent coronavirus numbers in the state and uses data from the COVID Tracking Project and U.S. Census Bureau.
The chances of exposure increase with the crowd size.
At a dinner party in South Carolina — or a group of 10 people — there’s about a 3.9% chance someone there is infected with the coronavirus based on Monday’s pandemic numbers in the state.
Increasing the crowd size to 100 people, which the model estimates is about the size of a wedding reception, brings the chances of exposure up to about 32.6%.
In larger crowds, such as concerts or large sporting events, the chances increase dramatically — to nearly 100%, the model shows.
At least 58,003 people total in South Carolina have tested positive for the coronavirus, with 1,532 new cases reported Monday. But state health officials have said cases are likely significantly undercounted as many go undetected.
About 86% of people in South Carolina who get the virus aren’t diagnosed, health officials estimate. That would mean more than 414,000 people have likely had the virus since March, The State newspaper reports.
The model calculates chances of exposure based on the number of cases circulating. It also takes into account “potential under-testing and reporting” and provides adjusted estimates as well.
For example, if the situation in South Carolina were five times the “current incidence,” the chances of exposure in a crowd of 10 people would jump to about 18%. If it were 10 times the incidence, the chances would hit 33%, the model shows.
In a crowd of 100 people, the chances of exposure would be 86.3% at five times the incidence and 98.2% at 10 times, the model shows.
The tool also breaks down the chances by county.
Users can again input the number of people in a crowd and the model calculates chances of exposure in each of South Carolina’s 46 counties given the reported coronavirus numbers that day.
In a crowd of 50 people, the chances of exposure would range from 75% to 99%. The chances of exposure are greater in Charleston County, at more than 99%.
Charleston County, home to a popular tourist city on the coast, has a high rate on infection at more than 301 cases per 100,000 residents, data from the S.C. Department of Health and Environmental Control show.
If the crowd size is decreased to 10 people, most counties would fall in the range of a 25% to 50% chance of exposure, with three — Barnwell, Charleston and Horry — falling in the 50% to 70% range.
However, if the crowd size is increased to 100 people, the chances would increase to 75% to 90% in most counties, with the chances in several — mostly on the coast — spiking above 99%.
Coastal South Carolina has been hit hard by the pandemic. Infection rates have been especially high among visitors to the state’s beaches, The Sun News reports. Health officials advised in June that anyone who has been to one of the beaches be tested for the virus.
“If you’ve gone to the beach, you’ve likely come in contact with somebody who is positive, but perhaps asymptomatic,” Joan Duwve, public health director at the S.C. DHEC, said in June.
