Assessment of the effectiveness of required weekly COVID-19 surveillance antigen testing at a university

Objectives To mitigate the COVID-19 pandemic, many institutions implemented a regimen of periodic required testing, irrespective of symptoms. The effectiveness of this”surveillance testing” requires assessment. Methods I fit a zero-inflated negative binomial model to COVID-19 testing and case investigation data between 1 November 2020 and 15 May 2021, from young adult subjects in one community. I compared the duration of symptoms at time of specimen collection in those diagnosed via (1) surveillance testing at a university, (2) the same university’s student health services, and (3) all other testing venues. Results The data comprised 2926 records: 393 from surveillance testing, 493 from student health service, and 2040 from other venues. About 65% of people with COVID-19 detected via surveillance testing were already symptomatic at time of specimen collection. Predicted mean duration of pre-testing symptoms was 1.7 days (95% CI 1.59 to 1.84) for the community, 1.81 days (95% CI 1.62 to 1.99) for surveillance, and 2 days (95% CI 1.83 to 2.16) for student health service. The modelled “inflated” proportions of asymptomatic subjects from the surveillance stream and the other/community stream were comparable (odds ratio 0.95, p = 0.7709). Comparing surveillance testing with the student health service, the proportion of “excess” zero symptom durations was signficantly higher in the former (Chi-square = 12.08, p = 0.0005) Conclusions Surveillance testing at a university detected 393 people with COVID-19, but no earlier in their trajectory than similar-aged people detected in the broader community. This casts some doubt on the public health value of such programs, which tend to be labor-intensive and expensive. 2 Three-question summary box What is the current understanding of this subject? Assessments of long-term operational effectiveness of COVID-19 “surveillance testing” have not been published. What does this report add to the literature? During the 2020-2021 academic year at one university, people with COVID-19 detected via compulsory weekly surveillance antigen testing were equally likely to be symptomatic at time of detection, and for just as long, as similar-aged people detected via testing venues in the community. What are the implications for public health practice? Surveillance testing programs during the pandemic consumed a large amount of time, money, and effort. In future respiratory pandemics, resources might be better devoted to other mitigation measures.