A new model projects a summer surge in coronavirus cases in Virginia if social distancing restrictions are lifted too soon.
The model developed by University of Virginia researchers using information specific to the state puts the peak at mid-to-late summer if Gov. Ralph Northam’s executive order is eased or lifted June 10.
The experts at UVA say limited testing in Virginia made it difficult to create the model. Northam said both private and public healthcare systems are ramping up testing and the models will be updated daily to give a clearer picture of when the outbreak will peak in Virginia.
Northam said social distancing is keeping the total number of COVID-19 cases down but it needs to continue and it’s too early to say for how long.
“Just as soon as we can get people’s lives back to normal, we will, but we have to do it safely,” he said.
The model projects coronavirus cases under five different scenarios — the worst projecting how the virus spreads unmitigated, and the best projecting how the virus spreads if current social distancing efforts stop the growth rate of the virus through June 10.
A middle-ground scenario projects what happens if mitigation efforts slow the growth rate but don't stop it.
Bryan Lewis, a research professor with the University of Virginia, said data so far indicate that social distancing and other mitigation efforts underway in Virginia are essentially stopping the growth rate. That's not to say that new cases aren't occurring, but that new cases are essentially holding steady.
Under the UVA model, new cases would increase only slightly from the current average of about 500 new confirmed cases a day through mid-June under the best-case scenario. Unfortunately, cases would then spike significantly, to a peak of about 12,000 new confirmed cases every day in mid-August.
If the virus were to spread unmitigated, on the other hand, new cases would spike to about 30,000 a day in early May and then drop precipitously to nominal levels by the end of June.
State officials said delaying the spike until August will give hospitals time to increase capacity and officials time to figure out how to avoid that late summer spike.
“People always adapt to ground reality,” said Madhav Marathe, a division director at the institute.
The University of Virginia numbers are significantly different from some other models.
A model from the Univeristy of Washington, for instance, measures different outcomes but on the whole paints a much more optimistic scenario than even the best-case scenario in the University of Virginia model. It essentially projects that cases will peak later this month, and that hospitalizations and deaths from the virus will fall to nominal levels by early June. That model assumes social distancing efforts remain in place through the end of May.
Virginia health secretary Daniel Carey said the various models all have different methodologies and strengths and weaknesses.
“This is not a crystal ball,” Carey said of the models. “These models change every single day, sometimes subtly and sometimes dramatically.”
Lewis also acknowledged the models' limitations. He said they struggle, for example, with how to account for the fact that other coronaviruses, like influenza, have large been seasonal phenomenons that fade away as spring transitions to summer.
Northam said his primary conclusion from the data is that Virginia must stay the course on social distancing for the foreseeable future.
“If we lift the stay-at-home order or social distancing too soon, if we try to rush to get our lives back to normal, the number of cases will spike higher and earlier,” Northam said.
For most people, the virus causes mild or moderate symptoms, such as fever and cough that clear up in two to three weeks. For some it can cause more severe illness and be life-threatening.
Non-essential businesses in Virginia are ordered to stay closed through April 23, but Northam plans to extend that and will announce a new date Wednesday.
“If we lift the stay-at-home order or social distancing too soon, if we try to rush to get our lives to normal, the number of cases will spike higher and earlier,” Northam said.
The Virginia Department of Health reported that its death count since the coronavirus pandemic began has increased from 141 to 149. New cases increased by roughly 475, with roughly 5,750 positive cases now confirmed in the state.
The Virginia Department of Health includes probable cases in its county-level data. For the state total NBC Washington is only including confirmed cases.