1. Epidemiological history (1) travel history from the infected area or within 21 days; (2) contact with febrile persons from or who have been to the infected area within 21 days; (3) contact with patients, their blood, body fluids, secretions, excretions or corpses within 21 days; (4) contact with infected animals. (2) Clinical manifestations (1) Early stage: acute onset, fever and rapid progress to high fever, accompanied by malaise, headache, myalgia, sore throat, etc., and may appear nausea, vomiting, abdominal pain, diarrhea, skin rash, etc. (2) Extreme stage: mostly appears after 3-4 days of illness. Persistent high fever, increased symptoms of infection poisoning and gastrointestinal symptoms, and different degrees of bleeding, including skin and mucous membrane bleeding, vomiting blood, hemoptysis, blood in the stool, hematuria, etc.; severe cases may have impaired consciousness, shock and multi-organ involvement, and mostly die from bleeding and multi-organ dysfunction within 2 weeks after the onset of the disease. 3.Laboratory tests The diagnosis can be confirmed if the suspected case meets one of the following conditions: (1) Positive nucleic acid test: the patient’s blood and other specimens are tested by RT-PCR and other nucleic acid amplification methods, and the results are positive. If the nucleic acid test is negative, but the disease duration is less than 72 hours, the test should be repeated after reaching 72 hours; (2) positive viral antigen test: collect the patient’s blood and other specimens, and test the viral antigen by ELISA and other methods; (3) isolation of the virus: collect the patient’s blood and other specimens, and isolate the virus by Vero, Hela and other cells; Ebola virus is a highly dangerous pathogen and must be isolated in a special laboratory facilities for virus isolation and identification. (4) Positive serum-specific IgM antibody test; positive conversion or 4-fold or more elevation of double serum-specific IgG antibodies in the recovery period compared to the acute phase; virus-specific IgM antibodies in the patient’s blood appear 2 to 9 days after onset and persist until 1 to 6 months after onset; IgG antibodies appear 6 to 18 days after onset and persist until more than 2 years after onset. The ELISA method established to detect IgG antibodies to Ebola virus using the carboxy-terminal polypeptide of the viral core protein prepared by genetic engineering as the antigen has high specificity and sensitivity. However, for some patients with very low titers of specific antibodies in the serum during the acute phase, detection of viral antigens or nucleic acids should be performed simultaneously. (5) Positive pathogenic tests in tissues. At present, the diagnosis is mainly made in infected areas in Africa by testing for Ebola virus-specific IgM and IgG antibodies and by examining viral antigens or nucleic acids. It has been demonstrated that detection of Ebola virus antigens and detection of viral nucleic acids are in almost 100% agreement and have high sensitivity.