<prompt> Hemagglutination is caused by which organism:Influenza virusMumpsAdenovirusParvovirus  <response>: Ans. a Influenza virusRef: Microbiology by Ananthanarayan and Paniker 8th ed. 429 A large number of viruses agglutinate erythrocytes from different species by the process known as Hemagglutination. Hemagglutination of influenza virus is due to presence of hemagglutinin spikes on the surface of virus. Viruses causing Hemagglutination are: Influenza Virus Measles Rubella Coxsackie Virus RhinoVirus Rabies Parainfluenza Virus Toga Virus EnteroVIrus Echo Virus Reo Virus 