摘要
许多猪流感患者，即便病情严重，但也没有发热症状，新病毒的这一奇怪特性可能会增加控制疫情的难度。美国前沿流行病专家上周于墨西哥检查了若干病例后如是说。发热是流感的显著特征，通常是发病时体温骤升至华氏104°（合摄氏40°）。由于许多传染病专家将发热视为流感最重要的症状，有无发热症状是检查病人的关键。
Many people suffering from swine influenza, even those who are severely ill, do not have fever, an odd feature of the new virus that could increase the difficulty of controlling the epidemic, said a leading American infectious-disease expert who examined cases in Mexico last week.
