The document provides a comprehensive overview of the poliovirus, including its definition, morphology, history, classification, replication cycle, transmission, pathogenesis, and prevention. It highlights key milestones in the understanding of poliomyelitis from the first clinical description in 1789 to the identification of the virus in 1908 and discovery of its strains in the 1930s. The virus is characterized as a single-stranded, non-enveloped virus that primarily spreads through the fecal-oral route, leading to paralysis by invading the central nervous system.

2. Polio Virus
By
Rani Summeya Seme 33

3. Outline
O Definition
O Morphology
O History
O Classification
O Replication cycle
O Transmission
O Pathogenesis
O Prevention

4. Definition
O Poliomyelitis
O Enterovirus
O Single strand + sense
O Diameter= 30nm
O Icosahedral
O Non enveloped
CD155 Receptor site

6. History
O 1789 first clinical description
O 1894 first outbreak of polio
O 1908 identification of polio virus
O 1930s Two strains of polio virus discovered
Karl Landsteiner &
Erwin Popper

7. Classification
O Group Group IV + ssRNA Virus
O Order Picornavirales
O Family Picornaviridiae
O Genus Enterovirus
O Species Enterovirus C
Subtype Polio Virus

8. Replication cycle
OAttachment
OPenetration
OUncoiling
OTranscription
OTranslation
OExit

9. Attachment

10. Penetration
OTwo types
O Pore Mediated Penetration
O Receptor Mediated Penetration

11. Pore Mediated Penetration

12. Receptor Mediated
Penetration

14. Transcription /Tanslation
Genome

15. Exit
OLysis 4 – 6 hour after initiation
OMechanism of viral release unclear
OEach dying cell release 10,000
virions

16. Transmission
Resides in
O Intestinal tract
O Mucus
O Fecal oral route
O Contaminated food & water

17. Pathogenesis
O Replicates in GIT
O Invades CNS
O Causes paralytic disease