It begins as an influenza-like illness with fever, malaise and myalgia and proceeds with cough (little sputum). dyspnoea and sometimes severe anoxia, marked confusion and coma.

• 发病时好似流感，有发热、乏力及肌痛，以后发生咳嗽(痰少)、气急。有时严重缺氧，显著的精神错乱及昏迷。