INFLUENZA A H1N1 INFECTION,Influenza A (swine). Representation of the presumed origin of swine influenza or influenza A. This new virus would be issue of various viruses (avian influenza virus, human influenza virus and swine virus) recombined in the organism of the pork. This virus is transmissible from the pork to the man through the air, and from the man to the man through the air and by contact. Insert on the replication of a virus in the body of a host. The viruses (in green) fix to the surface of the host-cell (in red) through receptors of this one that recognizes the virus ; they will then enable it to penetrate in the host-cell by endocytose. The RNA of the virus is transformed into RNAm ; it compels the host-cell to synthesize the constituents of the virus (proteins and RNA). These elements gather to the surface of the host-cell to form new H1N1 viruses in large quantity, that will invade the host-organism and spread the disease.