COVID-19 Test Strategy to Guide Quarantine Interval in University Student.

Area of Science:

• Public Health
• Infectious Disease Epidemiology
• Virology

Background:

• Current COVID-19 quarantine guidelines recommend 10-14 days for asymptomatic individuals, with recent updates suggesting 7 days with a negative PCR test.
• A university-based prospective cohort study was conducted to evaluate early PCR negativity as a predictor of day 14 negativity in asymptomatic students.

Approach:

• 101 asymptomatic students undergoing quarantine were enrolled.
• Nasopharyngeal swabs were collected for viral testing on days 3/4, 5, 7, 10, and 14.
• Concordant negative results were compared between earlier testing days and day 14 using exact binomial confidence intervals.

Key Points:

• 16% of students tested positive during quarantine. No positive tests were observed on days 10 or 14.
• Concordant negative rates for day 5, 7, and 10 versus day 14 were high (90-91%).
• No statistically significant difference was found in negative rates between earlier days and day 14.

Conclusions:

• The observed 16% positive rate underscores the continued necessity of quarantining close contacts of COVID-19 cases.
• This study offers the first direct evidence that asymptomatic university students (ages 18-44) are at low risk when released after a 7-day quarantine with a negative PCR test.