2005 Focus

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, and 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, marking a fatality rate over 30%. Since, the world has heightened its alert on the next influenza pandemic. Between 2004 and 2006, many Asian nations were attacked by high-pathogenic avian influenza (H5N1). Later, attacks on humans were continuously reported in Vietnam, Thailand, Cambodia, Indonesia, China, Turkey, Iraq and Azerbaijan, which had a fatality rate as high as 50%. There were even sporadic reports of limited human-to-human transmissions of the disease. In Taiwan, the surveillance of avian flu is in the charge of the Council of Agriculture, which keeps tabs on hogs as well as birds, chickens, ducks, and geese. But between December 2003 and March 2004 only low-pathogenic H5N2 was detected, leading to the destruction of 370,000 domestic poultry. Fortunately, no sign of high pathogenic H5N1 has ever been discovered. Taiwan’s Center for Disease control (CDC) has built multiple surveillance systems to detect human avian flu cases and unusual clustering of influenza-like illness. Furthermore, 12 virology laboratories belonging to medical centers have joined the laboratory surveillance system, which offer more information about influenza. Thanks to aggressive surveillance and case investigation, so far there is no human avian influenza case has been reported in Taiwan. Although H5N1 has not yet made effective human-to-human transmission, it has become an endemic in certain Asian countries, indicating the condition for a pandemic is being gradually built up. In the next few years, the avian flu currently hitting Asia threatens to trigger a pandemic.