Tahseen Kazmi, Muhammad Athar Khan.
Avian Influenza (Bird Flu) an emerging threat.
J Pak Med Assoc Jan ;56(5):232-3.

The emergence of avian influenza, caused by the highly pathogenic H5N1 Influenza A virus, is a cause for great concern since this virus has the potential to trigger a pandemic. Three such pandemics have occurred in the last century; in 1918, 1957 and 1968 causing million of deaths. The 1918 pandemic was the most severe accounting for 20-40 million lives.] Influenza viruses continue to evolve, and new antigenic variants (drift, strains) emerge constantly, giving rise to yearly epidemics. In addition, strains to which most humans have no immunity appear suddenly, and the resulting pandemics vary from serious to catastrophic. This is a review article.

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