Summary

Numerous American colleges and universities are planning to reopen for fall instruction. It is widely anticipated that the congregation of students will lead to new outbreaks of COVID‑19. Institutions have accordingly adopted policies and procedures designed to limit the spread of SARS-CoV-2, but the effectiveness of these procedures is currently unknown. Models are a useful tool for planning and scenario analysis in the absence of empirical information. However, there are several information gaps that make modeling of transmission within a university community particularly difficult, including how population segmentation (i.e. faculty, students, and staff) affects transmission; mixing rates among these segments; efficacy of generalized interventions such as wearing face masks, reducing student density, and installing infection barriers; and the extent of airborne, droplet, and surface contact transmission.

As with all current models, the following analysis is subject to these limitations. We are not, however, completely ignorant about the qualitative and quantitative properties of transmission by symptomatic and asymptomatic persons, the effectiveness of interventions, and usefulness of testing to identify asymptomatic carriers. In particular, compartmental models have been shown to be robust to a wide range of structural uncertainties and effectively represent the sometimes counter-intuitive properties of epidemics. Using the State of Georgia as an example, we modeled an outbreak of COVID‑19 for a typical large state university with a population of 50,000. Key findings of our analysis include:

  • Campus-based interventions are unlikely to prevent an epidemic of COVID‑19 within the campus community.
  • From 210 to 1618 imported infections may be expected with the arrival of students for Fall 2020.
  • To reduce the basic reproduction number (\(\mathcal{R}_{0}\)) to less than one, a testing program would need to administer approximately 6,181 tests per day at typical levels of protection (face masks, social distancing, etc.)
  • Effective containment of COVID‑19 at large institutions of higher education will require the widespread adoption of behavioral practices among students that reduce transmission of SARS-CoV-2 off-campus.

Model

We developed a compartmental model of COVID‑19 transmission on a university campus that includes asymptomatic transmission and accounts for surveillance testing and case isolation as well as generalized interventions. Individual persons are classified as Susceptible (\(S\)), Latent or presymptomatic (\(L\)), Asymptomatic (\(A\)), symptomatic and Infectious (\(I\)), or Removed through recovery or isolation (\(R\)) (Fig. ). The \(L\), \(A\), and \(I\) compartments are all considered infectious to varying degrees.