SARS-CoV-2 Epidemiology on a Public University Campus in Washington State

Weil, A. A.; Sohlberg, S. L.; O'Hanlon, J. A.; Casto, A. M.; Emanuels, A. W.; Lo, N. K.; Greismer, E. P.; Magedson, A. M.; Wilcox, N. C.; Kim, A. E.; Back, L.; Frazar, C. D.; Pelle, B.; Sibley, T. R.; Ilcisin, M.; Lee, J.; Ryke, E. L.; Craft, J. C.; Schwabe-Fry, K. M.; Fay, K. A.; Cho, S.; Han, P. D.; Heidl, S. J.; Pfau, B. A.; Truong, M.; Zhong, W.; Srivatsan, S. R.; Harb, K. F.; Gottlieb, G. S.; Hughes, J. P.; Nickerson, D. A.; Lockwood, C. M.; Starita, L. M.; Bedford, T.; Shendure, J. A.; Chu, H. Y.

Background: Testing programs have been utilized as part of SARS-CoV-2 mitigation strategies on university campuses, and it is not known which strategies successfully identify cases and contain outbreaks. Objective: Evaluation of a testing program to control SARS-CoV-2 transmission at a large university. Design: Prospective longitudinal study using remote contactless enrollment, daily mobile symptom and exposure tracking, and self-swab sample collection. Individuals were tested if the participant was (1) exposed to a known case, developed new symptoms, or reported high-risk behavior, (2) a member of a group experiencing an outbreak, or (3) at baseline upon enrollment. Setting: An urban, public university during Autumn quarter of 2020. Participants: Students, staff, and faculty. Measurements: SARS-CoV-2 PCR testing was conducted, and viral genome sequencing was performed. Results: We enrolled 16,476 individuals, performed 29,783 SARS-CoV-2 tests, and detected 236 infections. Greek community affiliation was the strongest risk factor for testing positive. 75.0% of positive cases reported at least one of the following: symptoms (60.8%), exposure (34.7%), or high-risk behaviors (21.5%). 88.1% of viral genomes (52/59) sequenced from Greek-affiliated students were genetically identical to at least one other genome detected, indicative of rapid SARS-CoV-2 spread within this group, compared to 37.9% (11/29) of genomes from non-Greek students and employees. Limitations: Observational study. Conclusion: In a setting of limited resources during a pandemic, we prioritized testing of individuals with symptoms and high-risk exposure during outbreaks. Rapid spread of SARS-CoV-2 occurred within outbreaks without evidence of further spread to the surrounding community. A testing program focused on high-risk populations may be effective as part of a comprehensive university-wide mitigation strategy to control the SARS-CoV-2 pandemic.