The retrospective study recruited 21 serious influenza patients (Criteria of Vietnamese Healthcare Ministry) includes 17 patients with A/H1Nl and 4 patients with A/H5N1. the remarks: - Mean age of patients in the 'study is young (H1Nl influenza A group is 27 + or - 15,2 year
H5Nl influenza A group is 26 + or - 3,4 year). - All patients in the study are fever and dysnea. Frequency of chest pain, dry tough, headache are 81 percent
71,4 percent
57 percent respectively. Frequency of myalgias, sore throat, rhinorrhea, sputum cough are 47,6 percent
42,9 percent
19 percent
28,6 percent respectively. - In H5Nl influenza, a group appears special symptoms: Petechia, hemoptysis, diarrhea, vomiting.