The research explained how the next influenza pandemic may arise and its possible outcome. This paper also discussed the history of Influenza happened in the year 1918, 1957, and 1968. Moreover this research used pictures and tables for effective illustrations of significant information.
An influenza pandemic is a universal outbreak of flu disease that takes place when a new type of influenza virus appears that people have not been exposed to before (Kilbourne ED. 1975). According to Kilbourne ED. (1975) that pandemic flu is a worldwide outbreak of disease that takes place as soon as a new influenza virus appears in humans, causes serious illness and then spreads effortlessly from person to person worldwide.
There are three types of influenza. Influenza A, B and C viruses are known to cause disease in humans. While influenza B and C viruses are strictly human pathogens, influenza Type A viruses are readily isolated from avian species, pigs and other animals. Influenza Type A viruses are divided into subtypes based on differences in the surface glycoprotein antigens, hem agglutinin (HA) and neuraminidase (NA). There are 14 known HA subtypes and 9 known NA subtypes. All of these subtypes have been isolated in birds but only 3 different HA and two different NA subtypes have been isolated in humans (See table bellow)
The influenza viruses are only one of its kinds amongst the respiratory viruses in that they undergo major antigenic variation (Stuart-Harris C. 1979). Antigenic drift entails minor antigen changes from one season to the next and may result in epidemic spread of the new strain. Antigenic shift entails major antigenic changes of the HA and NA molecules and happens merely with Influenza A viruses. These changes can result in the appearance of pandemic viruses.
In accordance with Stuart-Harris C. (1979) three worldwide outbreaks of influenza occurred in the 20th century: in 1918, 1957, and 1968. Of these, the 1918 Spanish Flu was the most severe, with 50 million or more deaths worldwide. The last 2 were in the era of modern virology and most thoroughly characterized. All 3 have been unofficially identified by the presumed sites of origin as Spanish, Asian, and Hong Kong influenza, respectively. According to Stuart-Harris C. (1979) they are now identified to represent 3 various antigenic subtypes of influenza Type A virus: H1N1, H2N2, and H3N2, respectively. Not classified as true pandemics are 3 prominent epidemics: a pseudo pandemic in 1947 with low death rates, an epidemic in 1977 that was a pandemic in children, and an abortive epidemic of swine influenza in 1976 that was feared to have pandemic potential. Major influenza epidemics show no predictable periodicity or pattern, and all differ from one another. Evidence implies that true pandemics with changes in hem agglutinin subtypes take place from genetic reassortment with animal influenza Type A viruses.
No one can foresee when a pandemic might take place, but public health experts think it is only a matter of time before the next one arises. Experts all over the world are watching the H5N1 avian flu condition in Asia very severely and are preparing for the probability that the virus may start to spread more easily and broadly from person to person. If this happens, the next