Optimizing COVID-19 control with asymptomatic surveillance testing in a university environment

Area of Science:

• Epidemiology
• Public Health
• Infectious Disease Modeling

Background:

• Asymptomatic and presymptomatic transmission of SARS-CoV-2 (COVID-19) complicates control via traditional non-pharmaceutical interventions (NPIs).
• US universities implemented asymptomatic surveillance testing to manage campus outbreaks during the 2020-2021 and 2021-2022 academic years.

Purpose of the Study:

• To develop a stochastic branching process model for COVID-19 dynamics at UC Berkeley.
• To advise on optimal control strategies for university environments, integrating behavioral interventions and surveillance testing.

Main Methods:

• Developed a stochastic branching process model incorporating group size limits, symptom-based isolation, contact tracing, and asymptomatic surveillance testing.
• Modeled COVID-19 transmission dynamics within a university setting.

Main Results:

• Behavioral interventions, such as group size limits (≤6) and rapid isolation of symptomatic cases, are cost-effective for epidemic control.
• Asymptomatic surveillance testing effectively manages uncertainty from infections without symptoms, prioritizing frequent testing with rapid turnaround over high sensitivity.
• Contact tracing amplifies the impact of all isolations, improving intervention effectiveness.
• Combining NPIs with surveillance testing reduces daily case count variability and allows for predictable epidemic trajectories.
• Targeted testing of high-risk individuals can control broader community epidemics.
• Asymptomatic surveillance remains effective in vaccinated settings for identifying breakthrough infections and reducing caseloads.

Conclusions:

• A combination of behavioral interventions and asymptomatic surveillance testing provides a robust strategy for controlling COVID-19 in university settings.
• The developed modeling tool can guide academic and professional communities in implementing effective return-to-work strategies.
• Frequent, rapid asymptomatic testing is crucial for managing SARS-CoV-2 transmission, especially given the prevalence of infections without symptoms.