1. Aged >=18 years, 2. Clinically diagnosed patients with COVID-19, including: on the basis of meeting the criteria for suspected cases, one of the following etiology evidence: (1) real-time fluorescent RT-PCR detection of SARS-Cov-2 nucleic acid samples in respiratory or blood samples, (2) Sequencing of viral genes in respiratory specimens or blood specimens, highly homologous to known SARS-Cov-2, 3. The interval between the onset of symptoms and random enrollment is within 7 days. The onset of symptoms is mainly based on fever. Cough, diarrhea or other related symptoms can be used for the evidence of onset symptoms if without fever.

1. Aged >=18 years, 2. Clinically diagnosed patients with COVID-19, including: on the basis of meeting the criteria for suspected cases, one of the following etiology evidence: (1) real-time fluorescent RT-PCR detection of SARS-Cov-2 nucleic acid samples in respiratory or blood samples, (2) Sequencing of viral genes in respiratory specimens or blood specimens, highly homologous to known SARS-Cov-2, 3. The interval between the onset of symptoms and random enrollment is within 7 days. The onset of symptoms is mainly based on fever. Cough, diarrhea or other related symptoms can be used for the evidence of onset symptoms if without fever.