Jinru Wu, Xinyi Liu, Jianjun Liu, et al
Published: May 22, 2020.
In this cross-sectional study, 10 of 60 patients previously diagnosed with and treated for COVID-19 had RT-PCR test results positive for SARS-CoV-2 from 4 to 24 days after index hospital discharge. As discharged patients were provided with home isolation instructions and local cases were rare, their positive results were presumed to be persistent viral shedding rather than reinfection. Consistent with previous studies showing prolonged viral shedding in the feces of patients with COVID-19, our results indicated that 6 patients had persistent viral shedding in the gastrointestinal tract after hospital discharge, including 1 patient (patient 2) who had positive results in both samples and showed RT-PCR positivity on March 27, 2020, a viral shedding duration of 56 days from illness onset. Lower threshold cycle values with anal swabs than those with nasopharyngeal swabs were identified in this study; however, the infectivity remains unclear, as infectious viruses have not been isolated from stool samples, to our knowledge.
This study was limited to a small number of discharged patients who had test results positive for SARS-CoV-2. Further studies using a larger cohort and isolation of the viable virus instead of RT-PCR testing are needed to define infectivity for continued disease management after hospital discharge.
Considering the RT-PCR positivity for SARS-CoV-2 among discharged patients with COVID-19 revealed by this and a previous study, appropriate personal protective equipment for medical staff might be important while collecting convalescent plasma, and the effects of convalescent plasma from clinically recovered patients with persistent viral shedding may need to be evaluated separately.