Background: While considerable clin. and epidemiol. data have been published during the 2019 novel coronavirus disease (COVID-19) pandemic, public health policies determining the duration quarantine and return to work for confirmed patients are still hampered by a lack of evidence. Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) of upper respiratory specimens remains the primary detection method for COVID-19. Initial studies have reported a median duration of SARS-CoV-2 viral RNA positivity ranging 9.5-20 days from symptom onset and a median duration of two days in seven asymptomatic patients. An addnl. study found that 90% of patients with mild disease achieved viral clearance by ten days from symptom onset. We report our findings regarding viral RNA positivity duration among a cohort of young patients with mild disease. Materials and Methods :Study Population Between March 20th, 2020, and May 10th, 2020, 219 soldiers were admitted to the Israel Defense Forces Medical Corps (IDF-MC) COVID-19 rehabilitation center following a pos. RT-PCR test for SARS-CoV-2, acquired from an oropharyngeal or nasopharyngeal swab. Recovery was defined as two sequential neg. RT-PCR results, after which soldiers were discharged. We retrospectively reviewed patient clin. records and RT-PCR results to determine the duration of SARS-CoV-2 positivity, defined as the period between symptom onset and the first of two consecutive neg. RT-PCR tests. For this study, we included recovered patients who presented mild symptoms and excluded patients who were asymptomatic, developed moderate disease or were lost to follow-up (Criteria available in the Supplementary Appendix). Data Collection: The medical staff at the rehabilitation center made telephone contact with patients upon receiving the initial pos. RT-PCR results. Patient demographics, epidemiol., medical history, and symptoms were gathered upon initial contact and documented in the IDF Computerized Patient Records (CPR), and a sep. database created for monitoring admitted patients. Upon admission to the rehabilitation center, patients filled an addnl. online questionnaire detailing demog. data along with current symptoms and vitals. During their stay at the rehabilitation center, monitoring physicians performed and documented daily telephone follow-up in an attempt to investigate symptom progression identify patients requiring further care. Patients who developed complications or experienced significant disease progression were referred to local tertiary hospitals for further care (Supplementary index). Specimen Collection and Viral RNA Detection of SARS-CoV-2 Nasopharyngeal and oropharyngeal swabs were obtained by specially trained IDF medics, paramedics or medical school students. Nasopharyngeal and oropharyngeal swabs were obtained within 48 h of being asymptomatic. In the case of a neg. result, an addnl. swab was obtained within 48 h. If a pos. result followed a neg. one, addnl. swabs were obtained until two consecutive neg. results were received. Definitions: Recovery was defined as two sequential neg. RT-PCR results, after which admitted soldiers were discharged. The primary outcome of time to viral RNA clearance was defined as the time period between symptom onset and the first of two consecutive neg. RT-PCR tests. This duration was then calculated with stratification for age, sex, and reported symptoms. Statistical Anal.: Continuous variables are described as medians with interquartile ranges (IQR) or means with standard deviations as deemed appropriate. Dichotomous variables such as the presence of symptoms are expressed as percentages. The date was aggregated in a dedicated spreadsheet and deidentified for the purpose of statistical anal. The duration of SARS-CoV-2 positivity was assessed using Kaplan-Meier curves. The data were analyzed using IBM SPSS version 25.0 (Armonk, NY: IBM Corp). Ethical Considerations: The study was approved by the IDF-MC institutional ethics committee, which waived the requirement for informed consent. Results: Between March 20th, 2020 and May 10th, 2020, 119 symptomatic patients with two consecutive neg. swabs were admitted to the IDF COVID-19 rehabilitation center, 84 (70.6%) males, 35 (29.4%) females with a median age of 21 (IQR 19-25). Symptoms reported upon admission included cough (75 [63.0%]), loss of smell (61 [51.3%]), headache (48 [40.3%]), loss of taste (47 [39.5%]) and fever (45 [37.8%]). 67 patients (56.36%) did not have any notable medical history (Supplementary Appendix). The clin. characteristics of the study population are detailed in Table 1. The median time for SARS-CoV-2 positivity in nasopharyngeal or oropharyngeal swabs in the study population was 21 days (IQR 15-27) from symptom onset, with a range of 4 to 45 days (Figure 1). The median time for viral RNA clearance stratified according to presenting symptom is detailed in Table 1.