Optimal test-assisted quarantine strategies for COVID-19 (preprint)

ABSTRACT

Background: Until herd immunity occurs for COVID-19, quarantine will remain a pillar for disease mitigation. A 14-day quarantine, although widely recommended for self-quarantine after potential infections and mandated by many government agencies can be physically and mentally stressful for those under quarantine and leads to lost productivity. Testing during quarantine is currently implemented by businesses and governments as a promising method to shorten the duration of quarantine. However, to our knowledge, no study has been performed to evaluate the performance of test-assisted quarantines and to identify the most effective choices of testing schedule. Methods: Based on statistical models for the transmissibility and viral loads of SARS-CoV-2 infections and sensitivity of various SARS-CoV-2 tests, we performed extensive simulations to evaluate the performance of quarantine strategies with one or more tests administered during quarantine. Sensitivity analyses were performed to evaluate the impact of model assumptions on the selection of optimal strategies. Findings: We found that SARS-CoV-2 testing can effectively reduce the length of quarantine without compromising safety. Whereas a single RT-PCR test performed before the end of quarantine can reduce the duration of quarantine to 10 days, two tests can further reduce the duration to 8-days and three tests with a highly sensitive RT-PCR test can justify a 6-day quarantine. More strategic testing schedules and one more day of quarantine are needed if tests are administrated with a less sensitive but more cost-effective antigen test. Interpretation: Testing during quarantine could substantially reduce the length of quarantine, reducing the physical and mental stress caused by long quarantines. With increasing capacity and lowered costs of SARS-CoV-2 tests, testing-assisted quarantines could be safer and more cost-effective than 14-day quarantines and warrant more widespread use.