Influenza A (H1N1) (also referred as swine flu) is a new influenza virus that has never before circulated among humans. This virus is not related to previous or current human seasonal influenza viruses. First detected in Mexico in April,2009,it has spread to many countries in the World. Swine flu is basically a misnomer. This was originally referred to as swine flu because laboratory testing showed that many of the genes in this new virus were very similar to those found in pigs in North America. Further on,it has been found that this new virus has gene segments from the swine,avian and human flu virus genes. The scientists call this a quadruple reassortant virus and hence this new (novel) virus is christened influenza-A (H1N1) virus.
