Updated COVID-19 case projections and county-level testing positivity rates released today by PolicyLab at Children’s Hospital of Philadelphia (CHOP) show transmission risk has rapidly increased across much of the northern U.S., including the Pacific Northwest and Midwest, with increasing risk now moving into New York and other parts of the Northeast.
The swift escalation of testing positivity rates in these regions suggests the negative consequences of cooler temperatures are taking hold sooner than the researchers anticipated, likely accelerated by community fatigue with mitigation strategies such as masking and distancing.
The resurgence risk that the researchers’ identified in the last two weeks in the Upper Midwest and Mountain States has now spread to much of the remaining northern states.
In the Pacific Northwest, forecasts have significantly worsened for Seattle, counties in eastern Washington and Bend, Ore.
Testing positivity rates are rising again throughout Michigan (except Detroit) and Indiana, heightening transmission risk across the entire Midwest.
Several concerning outbreaks on the east coast—including in central Pennsylvania, Ocean City, NJ, and Rockland County and Brooklyn, NY—are projected to result in widespread community transmission.
While forecasts for New England remain overall stable this week, the researchers observed modest increases in risk across communities in Connecticut, Rhode Island, Massachusetts and New Hampshire that will warrant close monitoring.
Most worrisome, however, are rising hospitalization rates in the Upper Midwest and Mountain States that have followed in the weeks since PolicyLab researchers first observed increasing resurgence risk in these regions.
This signals that the newly identified areas of concern, highlighted by the modeling data this week, could experience a similar trend in the near future.
This trajectory, plus the stabilization in case counts and testing positivity rates in more temperate states, such as Florida and Alabama, is additional evidence that colder weather may facilitate more efficient transmission of COVID-19.
“The simultaneous convergence of rising testing positivity rates, hospitalizations, and case counts across much of the northern U.S., makes this week’s forecasts among the most concerning that we have reported since Memorial Day,” said David Rubin, MD, MSCE, director of PolicyLab at CHOP and a professor of Pediatrics at the University of Pennsylvania’s Perelman School of Medicine.
“However, our projections are just that—projections—and we should not accept them as fate. There is still time for communities experiencing heightened transmission risk to turn their trajectories around with strong mitigation policies, and for those areas not yet seeing resurgence, to commit to proven prevention practices, such as masking and distancing.”
For more information, visit policylab.chop.edu