This document provides an overview of poliomyelitis (polio), including:
- Polio is a viral infection that can affect the spinal cord, causing muscle weakness and paralysis. There are three types that are transmitted via the fecal-oral route.
- The virus enters through the mouth and replicates in the gastrointestinal tract before potentially infecting cells in the central nervous system.
- Diagnosis involves testing samples of blood, cerebrospinal fluid, throat swabs, and feces through viral isolation, serology, or CSF analysis.
- Polio is predominantly seen in children under 3 years old and spreads more commonly in summer/rainy seasons. Prevention focuses on vaccination programs using both killed
3. INTRODUCTIION
• Poliomyelitis is a viral infection.
• The words polio means “grey” and myelin means “marrow indicating the spinal
cord” are derived from the Greek.
• Poliomyelitis literally meaning “ grey spinal cord inflammation”.
• A viral disease which may affect the spinal cord causing muscle weakness and
paralysis.
• Virus localized in the anterior horn cells of the spinal cord and certain brain steam
motor nuclei.
• 3 types : Spinal, Bulbar, Bulbo – spinal.
• Disease is more common in the summer (or) rainy season .
4. • The virus is
transmitted by
person to
person spread
mainly through
the fecal- oral
route or less
frequently by a
common vehicle
5. PATHOGENESIS
• The mouth is the portal of entry of the virus and primary multiplication of the virus
occurs at the site of implantation in pharynx and gastrointestinal track .
• The virus is usually present in the throat and in the stools before the onset of illness.
• One weeks after onset there is little virus in the throat but virus continues to be
excreted in the stools for several weeks .
• The virus invades local lymphoid tissue enters the blood streamand then may infect
cells of the central nervous system.
• Replication of polio virus in motor neurons of anterior horn and brain stem results in
cells destruction and causes the typical manifestation of poliomyelitis .
6.
7. LABORATORY DIAGNOSIS
• Samples to be collected blood, CFS, throat swab, feces.
• Transport immediately to lab in viral transport media (Hanks Balanced Salt Solution)
• Storage 4 Degree C (days) -20degree C (months to year)
• There are tests available
• Viral Isolation
• Serologic testing
• Cerebrospinal fluid (CSF) analysis
8. Viral isolation :
The likelihood of polio virus isolation is highest from stool specimens
Intermediate from pharyngeal swahs &very low from blood or spinal
fluid.
Serologic testing :
Testin A four – fold title rise between the acuts & convalescent specimens
suggests polio virus infection.
Cerebral fluid (CSF) analysis :
The cerebrospinal fluid usually contains an increased number of leukocyte
from 10 to 200 cells/ mm3 and a mildly elevated protein from 40 to 50 mg/100 ml .
9. EPIDEMIOLOGY
• Agent : Polio virus
• Type : three types ( type 1,2,3)
• Reservoir : man
• Infectious materials : faeces,oro – pharynged secretions.
• Incubation period : 7 to 14 days
• Period of communicability : 7 to 10 days
• Host age : 6 months to 3 years.
• Environment : rainy season ( june to september )
• Mode of transmission : faeco – oral route, droplet infection
10. PREVENTION
• General prevention :
Health promotion through environment sanitation .
Health education ( mode of spread, protective value of vaccination)
• Specific protection :
Passive immunization by human immunoglobulin
• Dose : (0.25-0.3 ml/ kg of body weight)
• Schedules : given either or before or very shortly after exposure to infection (not practical
• Active immunization :
Salk vaccine (intra muscular trivalent killed vacc)
Sabin vaccine (oral polio trivalent live attenuated va.)
11. CONTROL
• Sabin’s live attenuated vaccine.
• Grown in monkey kidney cells.
• Human diploid cells preserved at 4 degree C
• Multiple doses are given as oral drops .
• At present only vaccine given in our national programme of iimmunization .
• Boosts immunity with production IgG,IgM.
• And also IgA participated in prevention .