UW News

September 24, 2020

Colleges with primarily in-person instruction leading to thousands of COVID-19 cases per day in US

UW News

Cellphone traffic was one indicator of increased activity on a college campus.Dick Thomas Johnson/Flickr

As universities and colleges struggle to find the right combination of in-person and online classes combined with protective measures to help prevent the spread of the novel coronavirus, a new study by researchers from four institutions has reached a troubling conclusion.

Reopening university and college campuses with primarily in-person instruction is associated with a significant increase in cases of COVID-19 in the counties where the schools are located.

“Consequently, we are able to predict between 1,000 and 5,000 additional cases per day due to colleges reopening for face-to-face instruction, with our best estimate being somewhere around 3,000 cases per day or around 21,000 cases per week,” said study co-author Anirban Basu, professor of health economics and Stergachis Family Endowed Director of the CHOICE Institute at the UW School of Pharmacy.

More specifically, campuses with mostly in-person instruction contributed to increases in COVID-19 cases in their county by 0.024 cases per 1,000 residents. And, when students come from outside counties with surging cases, an additional 0.0119 per 1,000 residents come down with COVID-19.

“We don’t see similar spikes in cases for counties with colleges that reopened with primarily online instruction. The total spike attributed to face-to-face campus reopenings accounts for nearly 6 percent to 7 percent of all cases in the U.S. during this time,” Basu said.

Researchers from the University of North Carolina at Greensboro, Indiana University Bloomington, University of Washington and Davidson College conducted the study, which has not yet been peer reviewed. The study was posted Sept. 23 on the preprint server medRxiv and has been submitted to a journal for peer review.

“Given the timing of the mobility and case spikes,” Basu added, “these results are not likely a manifestation of additional testing or sick cases moving onto college campuses.”

The researchers sampled 1,409 colleges from July 15 to Sept. 13 and out of those classified 886 schools as conducting classes primarily in person, while 483 are teaching primarily online. Out of 1,142 U.S. counties examined in this study, only 779 contained a college in one of these categories, with 15 campuses not open during the sampling period. The researchers then compared these counties to counties without a college and looked at the periods of two weeks before the start of classes and two weeks after instruction began.

One of the signals the researchers used to determine the increase of visitors to a campus, whether for in-person instruction or on campuses with primarily online courses, was the increased presence of cellphones. Regardless of the type of instruction offered, the number of cellphones visiting campus increased significantly, in the week leading up to the start of classes and after classes had begun. However, cellphone traffic was higher on in-person campuses. And, counties with primarily online campuses did not see a statistically significant increase in COVID-19 cases.

“Our main data track cellphone movement on and off campuses and county-level COVID-19 daily reported cases,” Basu explained. “And, all evidence suggests there is a distinct local transmission component, given spikes in cases are happening two weeks after college opens. We also found spikes in cases to be higher for face-to-face colleges that drew students from communities that have seen recent spikes in cases.”

The researchers add that campus administrators and other local authorities should use these findings when considering additional strategies to mitigate COVID-19 outbreaks, and “think carefully” about cases in their counties as well as where students are coming from when planning their spring 2020 semesters.

Co-authors include Martin Andersen, Department of Economics, University of North Carolina at Greensboro; Ana Bento, School of Public Health-Bloomington, and Kosali Simon, O’Neill School of Public and Environmental Affairs, Indiana University; and Chris Marsicano, founding director of The College Crisis Initiative at Davidson College.


For more information, contact Basu at basua@uw.edu