Although each flu outbreak is different, yet the past four pandemics show some common features. This may be of relevance in handling the current swine flu pandemic which has infected over 30,000 people in 74 countries.
    A team of scientists dug up data about the last four flu pandemics. Their analysis, recently published in the New England Journal of Medicine, shows that the swine flu pandemic has already fulfilled one of the conditions — it is caused by a new variant of the flu virus family. ‘Higher death rate in 25-40 age group’
    The past four pandemic show some common features. The current swine flu pandemic, like the previous three, is caused by a new variant of the flu virus family. The current outbreak is not yet showing the other features, although it is still too early. Previous pandemics showed a markedly higher death rate among relatively younger population (25-45 years) unlike the normal flu that affects the young and elderly more.
    Reasons for this are unclear but it may be because of an over-reaction of the body’s immune system to the virus. This has implications for distribution of antiflu remedies. Past epidemics also show that the viruses responsible were much more easily transmissible.

Source: Times of India