As many as 750,000 North Carolina residents could become infected with the new coronavirus by the end of May if social distancing policies are allowed to lapse at the end of April, when they are currently set to expire, according to a new effort to model the spread of COVID-19 in North Carolina.
However, if people continue to stay apart and the governor’s stay-at-home order is extended through at least the end of May, only 250,000 people would contract the virus, the model suggests.
In that scenario with fewer cases, there would still be a 20% chance that North Carolina hospitals would see a surge of critically ill patients too large to handle at once, according to the model developed by epidemiologists from the University of North Carolina and Duke University. Without those extended measures, the hospitals would face near certain disaster.
The scientists stopped short of recommending a policy but clearly said the consequences of overwhelming the hospital system without continued social distancing would be dire.
During an N.C. Department of Health and Human Services media event Monday, Aaron McKethan, a Duke University adjunct professor and CEO of NoviSci, likened the effort of predicting the impact of the virus to one that North Carolinians know well: a hurricane forecast.
“It’s difficult to predict when a storm will hit our shores,” he said, especially when the weather is calm and the hurricane is far away. It could be a category 5 monster, or it could be a tropical storm.
“In an epidemic like COVID-19, we do have the ability to shape the hurricane’s direction and strength,” McKethan said.
The model will change over time, just as forecasts for storms also change, he said.
“We know that modeling is not a crystal ball,” said Dr. Mandy Cohen, secretary of the N.C. Department of Health and Human Services.
The scientists explained that failure to extend the order would result in a surge of people needing critical care at the same time.
Combined with extended social distancing, adding beds with sufficient staff and equipment could also make a difference. But experts said it would take a substantial number of beds.
Even if hospitals statewide increase the number of acute and intensive care unit beds by 4,000, it would only have a small effect on the chance of running out of beds for the most serious patients, said Mark Holmes, director of the Cecil G. Sheps Center for Health Services Research at UNC Chapel Hill.
Although other models offer different predictions, this modeling effort is also based on very specific attributes of North Carolina’s population, said Pia MacDonald, senior director and senior epidemiologist at RTI International and an adjunct associate professor at UNC Chapel Hill.
“This is a very contagious infectious disease,” MacDonald said. “If you run out of hospital beds and people cannot get access to the hospital beds and the care they need, you will get more deaths.”
The group continues to tweak the model in the hope of fine-tuning predictions.
They are also examining cellphone data to determine whether residents are complying with the state’s stay-at-home order and social distancing guidelines.