Sir Winston Churchill Secondary School, Vancouver, British Columbia.
Can J Infect Dis Med Microbiol. 2005 May;16(3):197-201. doi: 10.1155/2005/957360.
The purpose of the present article was to determine whether avian influenza (AI) is capable of causing a pandemic. Using research from a variety of medical journals, books and texts, the present paper evaluates the probability of the AI virus becoming sufficiently virulent to pose a global threat.Previous influenza A pandemics from the past century are reviewed, focusing on the mortality rate and the qualities of the virus that distinguish it from other viruses. Each of the influenza A viruses reviewed were classified as pandemic because they met three key criteria: first, the viruses were highly pathogenic within the human population; second, the viruses were easily transmissible from person to person; and finally, the viruses were novel, such that a large proportion of the population was susceptible to infection. Information about the H5N1 subtype of AI has also been critically assessed. Evidence suggests that this AI subtype is both novel and highly pathogenic. The mortality rate from epidemics in Thailand in 2004 was as high as 66%. Clearly, this virus is aggressive. It causes a high death rate, proving that humans have a low immunity to the disease.To date, there has been little evidence to suggest that AI can spread among humans. There have been cases where the virus has transferred from birds to humans, in settings such as farms or open markets with live animal vending. If AI were to undergo a genetic reassortment that allowed itself to transmit easily from person to person, then a serious pandemic could ensue, resulting in high morbidity and mortality. Experts at the World Health Organization and the United States Centers for Disease Control and Prevention agree that AI has the potential to undergo an antigenic shift, thus triggering the next pandemic.
本文旨在探讨禽流感（AI）是否有能力引发大流行。通过研究来自各种医学期刊、书籍和文本，本文评估了 AI 病毒变得足够致命从而构成全球威胁的可能性。回顾了上个世纪的过去的流感 A 大流行，重点关注死亡率以及将其与其他病毒区分开来的病毒特性。审查的每种流感 A 病毒都被归类为大流行，因为它们符合三个关键标准：第一，病毒在人类群体中具有高度致病性；第二，病毒易于在人与人之间传播；最后，病毒是新型的，以至于很大一部分人群易受感染。还对 AI 的 H5N1 亚型进行了批判性评估。有证据表明，这种 AI 亚型既新颖又具有高度致病性。2004 年泰国爆发的疫情死亡率高达 66%。显然，这种病毒具有攻击性。它导致高死亡率，证明人类对该疾病的免疫力较低。迄今为止，几乎没有证据表明 AI 可以在人类中传播。在农场或有活体动物出售的开放市场等环境中，病毒已从鸟类转移到人类的情况时有发生。如果 AI 发生遗传重组，使其能够轻易地在人与人之间传播，那么严重的大流行可能会随之而来，导致高发病率和死亡率。世界卫生组织和美国疾病控制与预防中心的专家一致认为，AI 有可能发生抗原转变，从而引发下一次大流行。
