Swinw Flu Essay

3235 Words13 Pages
Swine flu: The respiratory infection popularly known as swine flu is caused by an influenza virus first recognized in spring 2009, near the end of the usual Northern Hemisphere flu season. Technically, the term "swine flu" refers to influenza in pigs. Occasionally, pigs transmit influenza viruses to people, mainly hog farm workers and veterinarians. Less often, someone infected occupationally passes the infection to others. Swine influenza virus (SIV) or S-OIV (swine-origin influenza virus) is any strain of the influenza family of viruses that is endemic in pigs. the known SIV strains include influenza C and the subtypes of influenza A known as H1N1, H1N2, H3N1, H3N2, and H2N3 Classification Of the three genera of influenza viruses that cause human flu, two also cause influenza in pigs, with influenza A being common in pigs and influenza C being rare.[4] Influenza B has not been reported in pigs. Within influenza A and influenza C, the strains found in pigs and humans are largely distinct, although because of reassortment there have been transfers of genes among strains crossing swine, avian, and human species boundaries. Influenza C Influenza C viruses infect both humans and pigs, but do not infect birds.[5] Transmission between pigs and humans have occurred in the past.[6] For example, influenza C caused small outbreaks of a mild form of influenza amongst children in Japan[7] and California.[7] Because of its limited host range and the lack of genetic diversity in influenza C, this form of influenza does not cause pandemics in humans.[8] Influenza A Swine influenza is known to be caused by influenza A subtypes H1N1,[9] H1N2,[9] H2N3,[10] H3N1,[11] and H3N2.[9] In pigs, three influenza A virus subtypes (H1N1, H1N2, and H3N2) are the most common strains worldwide.[12] In the United States, the H1N1 subtype was exclusively prevalent among swine

More about Swinw Flu Essay

Open Document