Poliomyelitis

Poliomyelitis base information, mode of transmission, symptoms and its treatment

1. POLIOMYELITIS T. Ramesh Assistant Professor of Zoology Vivekananda College Tiruvedakam

2. 1. What is Polio? 2. Symptoms 3. Vaccine 4. History 5. Causes 6. Risk factors 7. Prevention

3. Poliomyelitis Infectious virus- Genus- Enterovirus Family- Picornaviridae Spread easily from person to person Viral infection that can cause paralysis and death Destruction of motor neurons in the central nervous system Polio infections: S ub-Clinical, Non-Paralytic & Paralytic

4. The most common Polio Infection Approximately- 95 % of all cases Asymptomatic and does not Central Nervous System Mild symptoms without paralysis Approximately- 1-5 % of all cases Affects Central Nervous System

5. The most serious cases and rare Full or partial Paralysis Three forms of paralysis i . Spinal polio- Affects the spinal ii. Bubar polio- Affects brain stem iii. Bulbospinal polio- Affects both Post polio syndrome- Symptoms after 35 years A TEM micrograph of poliovirus

6. Very Contagious Infectious Diseases Person-to-Person Oral- F ecal Route Oral-Oral route Poor Sanitation Contaminated Water & Food Incubation period 6 to 20 days A blockage of the lumbar anterior spinal cord artery due to polio (PV3) Poliomyelitis pathogenesis

7. Humans are the only known carrier Subclinical- asymptomatic Infected do not know that they have the virus and spread it.

8. It is very small- ranges 22 to 33 nm Single stranded – apx 7500 nucelotides Virus enclosed with icosahedral protein capsid. It can survive acid pH environment There are three serotypes of poliovirus: namely PV1, PV2 and PV3

9. A stool or pharynx sample from suspected/infected persons Cerebrospinal fluid Non-paralytic : Fever, Sore throat, headache, vomiting, pain in limbs, stiffness in the neck. Paralytic: Very similar symptoms like non-paralytic; with in a week loss of reflexes, severe muscle aches, Weakness, flaccid paralysis-one side Post Polio : Muscle or joint weakness and pain; exhaustion after minimal activity; difficult to breathing; swallowing, intolerance of cold temeparture ; concentration and memory difficulties, depression etc.

10. 1789- Michael Underwood –first record 1930- three strains were discovered 1953- Dr. Jonas Salk developed inactivated polio vaccine 1980- post polio symptoms identified 1981- Genome sequence 1999- inactivated polio vaccine replaced by oral polio vaccine

11. Country Wild cases Circulating vaccine- derived cases Transmission Status Type(s)  Afghanistan 14 endemic WPV1  Pakistan 8 endemic WPV1  DRC 17 cVDPV only cVDPV2  Syria 74 cVDPV only cVDPV2 Total 22 91    

12. Virus enters- mouth and nose Begins replication in the throat and intestines Poliovirus use immunoglobulin like a molecules- receptor for recognizing host cells CD155 hosts motor neurons allow virus to attach After attached these virus hijacks the cell assembly- cytolysis

13. Thank you