Objectives The aim was to determine whether various clinical specimens obtained from COVID-19 patients contain the infectious virus. Methods To demonstrate whether various clinical specimens contain the viable virus, we collected naso/oropharyngeal swabs and saliva, urine and stool samples from five COVID-19 patients and performed a quantitative polymerase chain reaction (qPCR) to assess viral load. Specimens positive with qPCR were subjected to virus isolation in Vero cells. We also used urine and stool samples to intranasally inoculate ferrets and evaluated the virus titres in nasal washes on 2, 4, 6 and 8 days post infection. Results SARS-CoV-2 RNA was detected in all naso/oropharyngeal swabs and saliva, urine and stool samples collected between days 8 and 30 of the clinical course. Notably, viral loads in urine, saliva and stool samples were almost equal to or higher than those in naso/oropharyngeal swabs (urine 1.08 ± 0.16–2.09 ± 0.85 log 10 copies/mL, saliva 1.07 ± 0.34–1.65 ± 0.46 log 10 copies/mL, stool 1.17 ± 0.32 log 10 copies/mL, naso/oropharyngeal swabs 1.18 ± 0.12–1.34 ± 0.30 log 10 copies/mL). Further, viable SARS-CoV-2 was isolated from naso/oropharyngeal swabs and saliva of COVID-19 patients, as well as nasal washes of ferrets inoculated with patient urine or stool. Discussion Viable SARS-CoV-2 was demonstrated in saliva, urine and stool samples from COVID-19 patients up to days 11–15 of the clinical course. This result suggests that viable SARS-CoV-2 can be secreted in various clinical samples and respiratory specimens.

Background: The coronavirus disease (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a major global public health issue. SARS-CoV-2 infection is confirmed by the detection of viral RNA using reverse transcription polymerase chain reaction (RT-PCR). Prolonged viral shedding has been reported in patients with SARS-CoV-2 infection, but the presence of viral RNA does not always correlate with infectivity. Therefore, the present study aimed to confirm the presence of viable virus in asymptomatic or mildly symptomatic patients in the later phase of the disease, more than two weeks after diagnosis. Method: Asymptomatic or mildly symptomatic COVID-19 patients who had been diagnosed with the disease at least two weeks previously and admitted to a community treatment center (CTC) from 15 March to 10 April 2020 were enrolled in this study. Nasopharyngeal and salivary swab specimens were collected from each patient. Using these specimens, RT-PCR assay and viral culture were performed. Result: In total, 48 patients were enrolled in this study. There were no significant differences in baseline characteristics between the asymptomatic and mildly symptomatic patient groups. RT-PCR assay and viral culture of SARS-CoV-2 were performed using nasopharyngeal and salivary swabs. The results of RT-PCR performed using salivary swab specimens, in terms of cycle threshold (Ct) values, were similar to those of RT-PCR using nasopharyngeal swab specimens. In addition, no viable virus could be cultured from swab specimens collected from the late-phase COVID-19 patients with prolonged viral RNA shedding. Conclusions: In conclusion, our study suggests that even if viral shedding is sustained in asymptomatic or mildly symptomatic patients with later phase of COVID-19, it can be expected that the transmission risk of the virus is low. In addition, saliva can be used as a reliable specimen for the diagnosis of SARS-CoV-2 infection.

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A colonic lipoma is a very rare benign tumor that is usually asymptomatic and is found incidentally by colonoscopy. Patients with a large colonic lipoma may present with symptoms such as abdominal pain, bleeding, and colonic obstruction or intussusceptions. We report two patients with large colonic lipomas and symptoms. Standard endoscopic submucosal dissection (ESD) was performed to remove the lipomas instead of conventional surgical bowel resection. No complications were observed during or after the procedure. The tumors were resected en bloc, and the patients were discharged 2 d after ESD with a regular diet. The results indicate that ESD can be applied as safe and effective treatment for a large colonic lipoma.