Transmission Dynamics in a University Town

GENERAL INFORMATION

Repository for the R code, Whitman County COVID-19 weekly reports, and Mathematica notebook for the manuscript:

Unexpected Transmission Dynamics in a University Town: Lessons from COVID-19;

Erin Clancey $^{1,\dagger,\ast}$, Matthew S. Mietchen $^{2,\dagger}$, Corrin McMichael $^3$ and Eric T. Lofgren $^{1}$;

$^1$ Paul G. Allen School for Global Health, Washington State University, Pullman, WA; $^{2}$ Carolina Population Center, University of North Carolina, Chapel Hill, NC; $^3$ Whitman County Public Health Department, Colfax, WA;

$^{\dagger}$ Authors contributed equally to this work; $^*$ Correspondence: erin.clancey@wsu.edu;

Public health policy at institutions of higher education was a pervasive challenge during the COVID-19 pandemic. During the second wave of COVID-19 in fall 2020, the re-opening of colleges and universities was controversial because incidence in young adults was on the rise. The migration of students back to institutional campuses worried many that transmission within student populations would spread into surrounding communities. However, many colleges and universities held stead fast to mitigation strategies and these efforts in many cases were successful, with many examples of limited spread into surrounding communities. Whitman County in Washington State is an example of a community, the city of Pullman, co-located with a large university, Washington State University (WSU), where the role of students returning to the area for the fall 2020 semester was contentious. Using COVID-19 incidence reported to Whitman County, we retrospectively study the transmission dynamics that occurred between the student and community subpopulations in fall 2020. Thus, we develop a two-population ordinary differential equation mechanistic model to infer transmission rates within and across the university student and community subpopulations. We use results from Bayesian analysis to determine if sustained transmission of COVID-19 occurred in Whitman County and the magnitude of cross-transmission from students to community members. We find these results are consistent with estimation of the time-varying reproductive number and conclude that the students returning to WSU-Pullman did not place the surrounding community in undue risk of COVID-19 during fall 2020.

ETL, MSM and EC were funded by contracts 75D30121P10551, 75D30120P07911 and 75D30122C15691 from the Centers for Disease Control and Prevention, as well as RAPID 2110109 from the National Science Foundation. ETL was also supported on R35GM147013 from the National Institutes of Health.