5.1. Suspected Cases
The cases comply with any item of A and any two items of B, or with 3 items of B as follows. (A) Epidemiological history: within two weeks before disease onset, 1. have a history of travel or residence in the district with case report; 2. have contacted the patients positive with nucleic acid detection; 3. have contacted with the patients with fever and respiratory symptoms from the district with case report; 4. disease onset in clustering. (B) Clinical manifestations: 1. Have fever and/or respiratory tract symptoms; 2. Have pneumonia with image characteristics mentioned above; 3. In early stage of the disease, have normal or decreased total number of leukocytes, or decreased lymphocyte count.