The thought of a murderous virus often conjures images of patients suffering from Ebola virus in Africa, SARS in Asia or hantavirus in the U.S.

• 提到杀手级病毒，经常让人想到的影像，是受非洲伊波拉病毒、亚洲SARS病毒，或是美国汉他病毒折磨的病人；