Following COVID-19 exposure, the Centers for Disease Control (CDC) recommends a 10–14-day quarantine for asymptomatic individuals and more recently a 7-day quarantine with a negative PCR test. A university-based prospective cohort study to determine if early polymerase chain reaction (PCR) negativity predicts day 14 negativity was performed. A total of 741 asymptomatic students in quarantine was screened and 101 enrolled. Nasopharyngeal swabs were tested on days 3 or 4, 5, 7, 10, and 14, and the proportion of concordant negative results for each day versus day 14 with a two-sided 95% exact binomial confidence interval was determined. Rates of concordant negative test results were as follows: day 5 vs. day 14 = 45/50 (90%, 95% CI: 78–97%); day 7 vs. day 14 = 47/52 (90%, 95% CI: 79–97%); day 10 vs. day 14 = 48/53 (91%, 95% CI:79–97%), with no evidence of different negative rates between earlier days and day 14 by McNemar’s test, p > 0.05. Overall, 14 of 90 (16%, 95% CI: 9–25%) tested positive while in quarantine, with seven initial positive tests on day 3 or 4, 5 on day 5, 2 on day 7, and none on day 10 or 14. Based on concordance rates between day 7 and 14, we anticipate that 90% (range: 79–97%) of individuals who are negative on day 7 will remain negative on day 14, providing the first direct evidence that exposed asymptomatic students ages 18–44 years in a university setting are at low risk if released from quarantine at 7 days if they have a negative PCR test prior to release. In addition, the 16% positive rate supports the ongoing need to quarantine close contacts of COVID-19 cases.
Digital Object Identifier (DOI)
NCI Cancer Center Support Grant (P30 CA177558).
The data presented in this study are available upon request from the corresponding author. The data are not publicly available due to privacy concerns.
Kolesar, Jill M.; Gayheart, Tyler; Poston, Lance; Monday, Eric; Forster, Derek; Belcher, Elizabeth; Jaiswal, Rani; Turner, J. Kirsten; Arnett, Donna K.; Durbin, Eric B.; Monroe, Joseph; Romanelli, Frank; Arnold, Susanne M.; Jennings, C. Darrell; Weiss, Heidi; and DiPaola, Robert, "Preliminary Research on a COVID-19 Test Strategy to Guide Quarantine Interval in University Students" (2022). Pharmacy Practice and Science Faculty Publications. 77.