英文摘要 |
Three influenza pandemics hit the world in the twentieth century, in 1918, 1957 and 1968 respectively. The 1918-19 pandemic took a toll of 20-40 million lives; the 1956-57 pandemic in Asia killed more than one million people, the 1968-69 pandemic claimed 700 thousand lives, also in Asia. In 1997, H5N1 avian influenza virus hit Hong Kong, registering 18 cases involving 6 deaths, a fatality rate over 30%. Since, the world has heightened its alert on the next influenza pandemic. Between 2004 and 2005, many Asian nations were attacked by high pathogenic avian influenza (H5N1). Later, the attack on humans was continuously reported in Vietnam, Thailand, Cambodia and Indonesia, which had a fatality rate as high as 50%. There were even reports of limited human-to-human transmission communication of the disease. |