<prompt> At present following types of influenza viruses are circulating in the world, except -H1N1H3N2Type C virusType B virus  <response>: INFLUENZA Causative agent : Ohomyxovirus, 3 types: A, B, C Type A: MC cause of outbreaksepidemics; Only cause of pandemics Type B Type C: Not circulating currently Currently circulating influenza viruses in world H1NI Type A - Cause of Swine Flu H2N2Tpye A H5N1Type A - Cause of An influenza Bird flu H3N2 H7N9 H5N6 Type B Ref: Park 25th edition Pgno : 169-171 