Methods

From February 1 to 14, 2020, clinical specimens, including serum, nasopharyngeal, and oropharyngeal swabs; urine; stool; and tissues from 73 hospitalized patients infected with SARS-CoV-2 were obtained in accordance with China Disease Control and Prevention guidelines and tested for SARS-CoV-2 RNA by using the Chinese Center for Disease Control and Prevention–standardized quantitative polymerase chain reaction assay. 5 Clinical characteristics of the 73 patients are shown in Supplementary Table 1. The esophageal, gastric, duodenal, and rectal tissues were obtained from 1 of the patients by using endoscopy. The patient’s clinical information is described in the Supplementary Case Clinical Information and Supplementary Table 2. Histologic staining (H&E) as well as viral receptor ACE2 and viral nucleocapsid staining were performed as described in the Supplementary Methods. The images of fluorescent staining were obtained by using laser scanning confocal microscopy (LSM880, Carl Zeiss MicroImaging, Oberkochen, Germany) and are shown in Figure 1. This study was approved by the Ethics Committee of The Fifth Affiliated Hospital, Sun Yat-sen University, and all patients signed informed consent forms.