<prompt> At present following types of influenza viruses are circulating in the world, except ?HIMH3N2H5N,B virus  <response>: Ans. is c i.e., H5N, At present three types of influenza viruses are circulating in the world: AHN1, A H3N2 and B viruses. WHO global surveillance activities have identified human infection with a new influenza virus called A in Hong Kong in mid1997. However, the possibility that the outbreak heralded a global influenza pandemic did not materialize. 