Orthoreovirus is a genus of viruses, in the family Reoviridae, in the subfamily Spinareovirinae. Vertebrates serve as natural hosts. There are currently five species in this genus including the type species Mammalian orthoreovirus. Diseases associated with this genus include: mild upper respiratory tract disease, gastroenteritis, biliary atresia. mammalian orthoreovirus type 3 (strain dearing-T3D) induces cell death preferentially in transformed cells and therefore displays inherent oncolytic properties.