River’ s Postu|ates T.M. River, 1937 Modified from Koch's Postulates(proof of bacterial diseases) 1. Isolate virus from diseased hosts Cultivation of virus in host cells 3. Proof of filterability 4. Production of a comparable disease when the cultivated virus is used to infect experimental animals 5. Re-isolation of the same virus from the infected experimental animal 6. Detection of a specific immune response to the virusRiver’s Postulates  T.M. River, 1937  Modified from Koch’s Postulates (proof of bacterial diseases) 1. Isolate virus from diseased hosts. 2. Cultivation of virus in host cells. 3. Proof of filterability. 4. Production of a comparable disease when the cultivated virus is used to infect experimental animals. 5. Re-isolation of the same virus from the infected experimental animal. 6. Detection of a specific immune response to the virus