Log in to MyACC
SARS-CoV-2 Screening Strategies to Permit Safe Reopening of College Campuses
Quick Takes
- This analytic modeling study suggests that frequent screening (every 2 days) of all students with a low-sensitivity, high-specificity test might be required to control outbreaks with manageable isolation dormitory utilization at a justifiable cost.
- Of note in colleges that can achieve strict adherence to behavioral guidelines, the reproductive numbers (Rt) may be lower, perhaps approaching 1.0-1.5, and less frequent testing may be required.
- While testing is important, successful colleges will work with faculty, students, and employees as well as surrounding communities to reduce the influx of new infections and to limit spread through appropriate use of social distancing, wearing masks, increased cleaning and ventilation, and performing robust contact tracing.
Study Questions:
What screening performance standards for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) would permit the safe return of students to US residential college campuses for the fall 2020 semester?
Methods:
The investigators conducted an analytic modeling study, which included a hypothetical cohort of 4,990 students without SARS-CoV-2 infection and 10 with undetected, asymptomatic SARS-CoV-2 infection at the start of the semester. The decision and cost-effectiveness analyses were linked to a compartmental epidemic model to evaluate symptom-based screening and tests of varying frequency (i.e., every 1, 2, 3, and 7 days), sensitivity (i.e., 70%-99%), specificity (i.e., 98%-99.7%), and cost (i.e., $10/test-$50/test). Reproductive numbers (Rt) were 1.5, 2.5, and 3.5, defining three epidemic scenarios, with additional infections imported via exogenous shocks. The model assumed a symptomatic case fatality risk of 0.05% and a 30% probability that infection would eventually lead to observable coronavirus disease 2019 (COVID-19)-defining symptoms in the cohort. Model projections were for an 80-day, abbreviated fall 2020 semester. This study adhered to US government guidance for parameterization data. The main outcomes measures were cumulative tests, infections, and costs; daily isolation dormitory census; incremental cost-effectiveness; and budget impact.
Results:
At the start of the semester, the hypothetical cohort of 5,000 students included 4,990 (99.8%) with no SARS-CoV-2 infection and 10 (0.2%) with SARS-CoV-2 infection. Assuming an Rt of 2.5 and daily screening with 70% sensitivity, a test with 98% specificity yielded 162 cumulative student infections and a mean isolation dormitory daily census of 116, with 21 students (18%) with true-positive results. Screening every 2 days resulted in 243 cumulative infections and a mean daily isolation census of 76, with 28 students (37%) with true-positive results. Screening every 7 days resulted in 1,840 cumulative infections and a mean daily isolation census of 121 students, with 108 students (90%) with true-positive results. Across all scenarios, test frequency was more strongly associated with cumulative infection than test sensitivity. This model did not identify symptom-based screening alone as sufficient to contain an outbreak under any of the scenarios considered. Cost-effectiveness analysis selected screening with a test with 70% sensitivity every 2, 1, or 7 days as the preferred strategy for an Rt of 2.5, 3.5, or 1.5, respectively, implying screening costs of $470, $910, or $120, respectively, per student per semester.
Conclusions:
The authors concluded that screening every 2 days using a rapid, inexpensive, and even poorly sensitive (>70%) test, coupled with strict behavioral interventions to keep Rt <2.5, is estimated to maintain a controllable number of COVID-19 infections and permit the safe return of students to campus.
Perspective:
This analytic modeling study suggests that frequent screening (every 2 days) of all students with a low-sensitivity, high-specificity test might be required to control outbreaks with manageable isolation dormitory utilization at a justifiable cost. Of note, symptom-based screening alone was not sufficient to contain an outbreak, and safe reopening may require screening every 2 days, unwavering vigilance, and attention to robust prevention practices. However, the authors acknowledge that in colleges that can achieve strict adherence to behavioral guidelines, the Rt may be lower, perhaps approaching 1.0-1.5, and less frequent testing may be required. It seems reasonable that before diverting resources to test every 2 days, the best-prepared campuses will execute a combination of strategies to reduce the influx of COVID-19 from outside and to limit spread once on campus. While testing is important, successful colleges will work with faculty, students, and employees as well as surrounding communities to reduce the influx of new infections and to limit spread through appropriate use of social distancing, wearing masks, increased cleaning and ventilation, and performing robust contact tracing.
Clinical Topics: Cardiovascular Care Team, COVID-19 Hub, Prevention
Keywords: Contact Tracing, Coronavirus Infections, Cost-Benefit Analysis, COVID-19, Diagnostic Tests, Routine, Disease Outbreaks, Faculty, Primary Prevention, Masks, Sensitivity and Specificity, severe acute respiratory syndrome coronavirus 2, Psychological Distance, Students
< Back to Listings
