LAUSR

To the Editor, While considerable clinical and epidemiological data have been published during the coronavirus disease‐2019 (COVID‐19) epidemic caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) 2019, few studies have discussed the viral dynamics in young and mild patients, relevant towards instituting public health policies. Real‐time reverse transcriptase‐polymerase chain reaction (RT‐PCR) of upper respiratory specimens remains the primary detection method for COVID‐19.2‐4 Initial studies have reported a median duration of SARS‐CoV‐2 viral RNA positivity from ranging between 9.5 and 20 days from symptom onset5‐7 and a median duration of two days in seven asymptomatic patients. We report our findings regarding the duration of viral RNA positivity among a cohort of young patients with mild COVID‐19 disease. In March 2020, the Israel Defense Forces Medical Corps (IDF‐MC) instituted a rehabilitation center for confirmed COVID‐19 patients. Between 20th March 2020 and 5th May 2020, 219 soldiers were admitted to the rehabilitation center following a positive RT‐PCR test for SARS‐CoV‐2 acquired from an oropharyngeal or nasopharyngeal swab. Recovery was defined as two consecutive negative RT‐PCR results, after which admitted soldiers were discharged. We retrospectively reviewed patient clinical records and RT‐PCR results to determine the duration of viral positivity, defined as the time period between symptom onset and the first of two negative RT‐PCR tests. We included recovered patients who presented mild symptoms and excluded patients who were asymptomatic, developed moderate disease or were lost to follow‐up (Appendix S1). As of 10th May 2020, 119 symptomatic patients with two consecutive negative swabs were admitted to the IDF COVID‐19 rehabilitation center, 84 (70.6%) males, 35 (29.4%) females with a median age of 21 (interquartile range [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%]). Total of 67 patients (56.36%) did not have any notable medical history (Supplementary Appendix). The clinical 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. The median time of viral RNA detection was stratified according to presenting symptom is detailed in Table 1. Determining the viral dynamics and natural history of SARS‐CoV‐2 in different populations is crucial towards instituting public health policies and granting clearance for infected patients. The results of this study suggest that in young and healthy adult patients with COVID‐19, the median duration of viral positivity is around three weeks. This duration is higher than that of previous reports which reported a