PHILADELPHIA — New COVID-19 case projections and county-level test positivity data released Oct. 21st by PolicyLab at Children’s Hospital of Philadelphia (CHOP) forecast a continued deteriorating situation throughout the Midwest and Mountain States, raising greater concern for major cities such as Chicago, Indianapolis and Denver. The model’s forecasts have also worsened for parts of the South—including Arizona’s metropolitan areas, counties across northern Texas and states in the Southeast—but show case counts will rise more slowly over the next four weeks in the Pacific Northwest and Northeast than in the central part of the country.

Increasing test positivity rates across the Midwest suggest this region’s outbreak will only intensify over the next month. The researchers now project most counties in Michigan, Ohio, and Indiana will see explosive growth in case counts, following recent similar trends witnessed in Wisconsin and Minnesota. Rapidly increasing hospitalization rates have more than doubled in the last few weeks in many Midwestern cities, adding significant concern to the PolicyLab forecasts. The fall surge is also not expected to subside in the Mountain States, with Colorado and Idaho projected to see some of the most widespread community transmission in the country into late November. The researchers’ forecasts for Reno and Las Vegas, Nevada, are beginning to worsen again, as well.

Resurgence risk has increased across much of the Southwest and Southeast. Following some relief from the summer wave, Arizona’s Maricopa (Phoenix), Pinal, and Pima counties are expected to see growth in case counts again over the next four weeks. Test positivity rates and hospitalizations are up in counties across northern Texas, including Dallas, Wichita, El Paso and Lubbock. Metropolitan areas in southeastern states, such as Nashville, Tenn., Atlanta, Ga. and Greenville, S.C., are also at risk of widespread community transmission as the weather turns colder in that region. Furthermore, the researchers observed early signals of resurgent transmission risk in the California’s Bay Area, along the southeast coast of Florida and throughout several parishes in Louisiana, which suggest the fall wave could spread even further.

There are some signs of optimism coming from the Pacific Northwest and Northeast, where PolicyLab’s model projects case counts and testing positivity rates will grow at a much slower pace than other parts of the country. Hospital occupancy plateaued last week across Oregon, Washington and Massachusetts, and the researchers are encouraged to see targeted mitigation response plans have slowed the rate of growth in case incidence in New York City, where hospitalizations rates slowed last week, as well. These data are encouraging for the continued safe reopening of schools in many areas.

PolicyLab also released new guidance today for in-person learning during the pandemic that reflects the latest evidence on children’s risk of contracting and transmitting COVID-19, as well as the success many schools have had with multi-layered strategies to maintain in-person learning while also protecting students, teachers and staff.

“We’re clearly in the middle of a fall wave, and much of the country is projected to see case counts dramatically rise over the next four weeks, warranting difficult discussions in school districts for when to suspend in-person learning, whether for a classroom or a whole school,” 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. “Yet, for schools in those parts of the U.S. that aren’t seeing accelerated growth of COVID-19 cases and hospitalizations, we’re advising education leaders that safe reopenings can still occur with strong safety plans, but that they will need to lean heavily on the advice of local health departments that can guide more informed decisions on when to close based on evidence of linked transmission between and among students and staff within a school.”

For additional comments from COVID-Lab’s lead investigators and collaborators on their updated forecasts and school reopening guidance, read this blog post: