Polio virus

2. ENTEROVIRUSES
2DWD
• Enteroviruses are a genus of the picornavirus family
which replicate mainly in the gut.
• Single stranded naked RNA virus with icosahedral
symmetry.
• Unlike rhinoviruses, they are stable in acid pH.
• Capsid has 60 copies each of 4 proteins, VP1, VP2, VP3
and VP4 arranged with icosahedral symmetry around a
positive sense genome.

3. ENTEROVIRUSES
3DWD
• At least 71 serotypes are known: divided into 5
groups
– Polioviruses
– Coxsackie A viruses
– Coxsackie B viruses
– Echoviruses
– Enteroviruses (more recently, new enteroviruses
subtype have been allocated sequential numbers
(68-71))

4. ENTEROVIRUSES HISTORY
4DWD
• Poliovirus - first identified in 1909 by inoculation of specimens into
monkeys. The virus was first grown in cell culture in 1949 which became
the basis for vaccines.
• Coxsackieviruses - In 1948, a new group of agents were identified by
inoculation into newborn mice from two children with paralytic disease.
These agents were named Coxsackieviruses after the town in New York
State. Coxsackieviruses A and B were identified on the basis of the
histopathological changes they produced in Newborn mice and their
capacity to grow in cell cultures.
• Echoviruses - were later identified which produced cytopathic changes in
cell culture and was nonpathogenic for newborn mice and subhuman
primates.
• More recently, new Enterovirus types have been allocated sequential
numbers (68 - 71).

5. GENERA OF
PICORNAVIRUSES
5DWD
Enterovirus
Poliovirus
Coxsackie A and B
Echo
Other enteroviruses
Diseases of the human (and other) alimentary tract
(e.g. polio virus)
Rhinovirus Disease of the nasopharyngeal region (e.g. common cold virus)
Cardiovirus Murine encephalomyocarditis, Theiler's murine
encephalomyelitis virus
Aphthovirus Foot and mouth disease in cloven footed animals
Hepatovirus Human hepatitis virus A
Others Drosophila C virus, equine rhinoviruses, cricket paralysis virus

6. CATAGORIES OF
ENTEROVIRUSES
6DWD
VIRUS SEROTYPES CLINICAL DISEASES
Polioviruses 3 types Asymptomatic infection, viral meningitis,
paralytic disease, poliomyelitis
Coxsackie A viruses 23 types ( A1-A22, A24) Viral meningitis plus, rash, ARD, myocarditis,
orchitis
Coxsackie B viruses 6 types (B1-B6) Viral meningitis, but no orchitis
Echoviruses 32 types Viral meningitis, with orchitis
Other Enteroviruses 4 types(68-71) Viral meningitis,

7. PROPERTIES OF
ENTEROVIRUSES
7DWD
PROPERTY ENTEROVIRUSES
Size (nm) 22 – 30
Capsid Form Icosahedral
Polypeptide VP1, VP2, VP3, VP4
RNA Type SS – PS
RNA Molecular Weight 2000,000 – 2600,000
Acid Stable
Optimal Temp.for growth (0 C) 370
C
Density in Cesium chloride (g / m) 1 . 34

8. TRANSMISSION OF
ENTEROVIRUSES
8DWD
• Fecal – oral route: poor hygiene, dirty
diapers( especially in day-care settings)
• Ingestion via contaminated food and water
• Contact with infected hands
• Inhalation of infectious aerosols

9. PATHOGENESIS OF
ENTEROVIRUSES
9DWD

10. Rhino,echo,
coxsackie,polio
Replication in
oropharynx
Primary viremia
Target Tissue Secondary viremia
Skin Muscle Brain Meninges Liver
Echo
Coxsackie
A
Echo
Coxsackie
A, B
Polio
Coxsackie
Echo
Polio
Coxsackie
Echo
Coxsackie
PATHOGENESIS OF ENTEROVIRUSES

11. POLIOMYELITIS
11DWD
• Poliomyelitis (polio) is a highly infectious viral
disease, which mainly affects young children.
The virus is transmitted through contaminated
food and water, and multiplies in the intestine,
from where it can invade the nervous system.

12. POLIOMYELITIS
12DWD
• Polio = gray matter, Myelitis = Inflammation of the
spinal cord.
• Involves CNS, produces serious Illness.
• Causes Destruction of Motor Neurons in Spinal cord.
• Produces FLACID PARALYSIS.
• India has still has many cases of Poliomyelitis.

13. POLIO – AN ENTEROVIRUS
13DWD
• Poliovirus, the causative agent of
poliomyelitis, is a human enterovirus and
member of the family of Picornaviridae.
Poliovirus is composed of a RNA genome and
a protein capsid. The genome is single-
stranded positive-sense RNA genome that is
about 7500 nucleotides long. The viral
particle is about 300 Angstrom in diameter
with icosahedral symmetry.

14. CLASSIFICATION OF
POLIOVIRUS
14DWD
• Type 1 - Brunhilde and Mahoney.
• Type 2- Lansing and MEFI.
• Type 3- Leon and Salkett.

15. 15
CLASSIFICATION OF
POLIOVIRUS
DWD
• Size is 27 nm
• Contains 4 viral protein
VP1 to VP 4
• VP1 Carries the major
antigenic site, and
combines with type
specific neutralizing
antibodies

16. PROPERTIES OF POLIOVIRUS
16DWD
• Typical Entero virus.
• Inactivated at 550 c for 30 mt.
• Chlorine at 0.1 ppm
• Ether is not effective.
• Animal susceptibility.
Monkey brain
Requires Primate specific membranes.
Contains 3 Antigenic types 1,2,3
Can be differentiated by ELISA and CF methods.

17. POLIO INFECTION
17DWD
• Incubation 3 – 21 days
• On average 14 days
• Predisposing factors.
Severe muscular activity can lead to paralysis, as it
increases the blood flow
May produce paralysis in the limb or bulbar region
Injecting vaccines with adjuvant can predispose to
paralysis
Patients who underwent tonsillectomy have higher
incidence as Ig G secretion is reduced
Rarely oral Polio vaccine produces poliomyelitis.

18. PATHOLOGY &
PATHOGENESIS
18DWD
• Destroy the Anterior horn cells of the Spinal Cord
• Do not Multiply in Muscles only muscles manifest
with weakness and flaccid paralysis result is
secondary.
• Occasionally produce
Myocarditis,
Lymphatic hyperplasia.

19. PATHOLOGY &
PATHOGENESIS
19DWD
• Enter through Mouth,
• Multiplies in Oropharynx tonsils and Intestines,
• Excreted in Stool.
• Enters the CNS from Blood.
• Spread along the Axons of peripheral nerves to CNS.
• Progress along the fibers of the lower motor neurons
spinal cord or brain.

20. VIRUS INFECTION PROCESS
20DWD
• The polio virus infects human cells by binding to an immunoglobulin-like
receptor called CD155 (poliovirus receptor).
• The exact mechanism that poliovirus uses for entering the cell is
unknown. However, the interaction of poliovirus and CD155 causes a
change in the shape of the viral particle that is needed to enter the cell
• There are two thesis' for the way the viral nucleic acid to enters the cell.
The first thesis is that the RNA of poliovirus is injected into the host cell
through a pore in the membrane of the host cell. The second, and the
one that is most likely and has the most support through research, is that
the poliovirus is taken in by the host cell through endocytosis.
• Poliovirus has ssRNA. Also known as single-strand RNA.

21. VIRUS INFECTION PROCESS
21DWD
• The genome inside poliovirus can be used as mRNA and immediately
translated by the host cell
• Inside the host cell, the virus then takes over the cell’s translation
machinery then causes inhibition of cellular protein synthesis. This favors
the virus.
• The poliovirus mRNA is then translated into a long polypeptide which is
cleaved into 10 individual viral proteins
• These proteins range from RNA polymerase to the proteins of the viral
capsid
• Translation of the viral RNA occurs by an IRES-mediated (internal
ribosome entry site) mechanism
• The IRES is the extremely long 5’ end of the poliovirus’ mRNA.
• The assembly of viral particles is not fully understood.
• The particles leave the host cell 4-6 hours after the initial infection. Each
dying host cell can release 10,000 polio virions.
• This means poliovirus is lytic

22. PATHOLOGY &
PATHOGENESIS
22DWD

23. CLINICAL MANIFESTATIONS
23DWD
• In apparent, Only 1% manifest with clinical features.
• Can lead to permanent paralysis.
• Incubation 7-14 days, ( 3-35 )
• May be abortive Poliomyelitis,
Only Fever, Malaise, Drowsiness,
Non paralytic Poliomyelitis,
Aseptic Meningitis.

24. 24
0 20 40 60 80 100
Percent
Asymptomatic Minor non-CNS illness
Aseptic menigitis Paralytic

25. PARALYTIC POLIOMYELITIS
25DWD
• Manifest as Flaccid Paralysis.
( Caused due to damage to
Lower Motor Neurons.)
• Partial recovery within 6
months.
• Patient may continue with life
time disability
• Can involve Spinal cord, and
Bulbo spinal region
• Bulb spinal involvement can
paralyze respiratory muscle
and lead to Respiratory
failure

26. PARALYTIC POLIOMYELITIS
26DWD

27. ASEPTIC MENINGITIS
27DWD
• Present with Non paralytic form with stiffness and
pain in the back and neck region
• Lasts for 2 -10 days
• Recovery rapid and complete
• On rare occasions advance to paralysis

28. LABORATORY DIAGNOSIS
28DWD
• Viral isolation from
Throat swabs,
Rectal swabs.
Stool specimens,
• Transported in frozen containers.
• Produce cytopathic effect on
Human and Monkey cells
• Produce cytopathic effects.

29. VIRAL ISOLATION
29DWD
• From feces - present in 80% of cases in 1st
week
• In 50 % till 3rd week
• In 25 % till several weeks
• Collect the fecal sample at the earliest.
• Primary monkey kidney is the ideal cell line
for isolation of virus
• Viral isolation must be interpreted with
caution and clinical presentation

30. LABORATORY DIAGNOSIS
(SEROLOGY)
30DWD
• Estimation of Antibodies IgM
• A paired sample is essential.
• ELISA
• CFT
• Neutralisation.

31. IMMUNITY
31DWD
• Permanent type specific.
• 1 and 2 types have Heterotypic resistance.
• Mother to Off spring immunity lasts for less
than 6 months.

32. EPIDEMIOLOGY
32DWD
• Endemic
• Epidemic
• Hygiene plays in spread of diseases.
• Children < 5 in Developing countries.

33. PREVENTION & CONTROL
33DWD
• Sabin’s Live attenuated vaccine
• Grown in Monkey kidney cells, Human Diploid cells.
Preserved at 40 C
• Multiple doses are given
• Given as oral Drops
• At present only vaccine given in our National
Programme of Immunization
• Boosts Immunity with Production IgG ,IgM
• And also IgA Participate as participant in
Prevention.

34. VACCINATION SABIN'S-
ORAL ADMINISTRATION
34DWD
• Sabin’s vaccine is administered orally.
• Contains
Type 1 – 10 lakh,
Type 2- 2 lakh
Type 3- 3 Lakh.
The virus are stable with Mg cl.

35. ORAL POLIO VACCINE ( SABIN’S)
35DWD
• Highly effective in
producing immunity to
poliovirus
• 50% immune after 1 dose
• >95% immune after 3
doses
• Immunity probably
lifelong

36. ADVANTAGES OF LIVE VACCINE
36DWD
• Induces long lasting immunity.
• Induces local immunity in the form of IgA
production ( gut immunity).
• Administered orally, without the need of sterile
syringes.

37. DISADVANTAGES OF LIVE VACCINE
37DWD
• The only disadvantage of this vaccine is the vaccine
strain particular type 3 strain can reverts to
virulerence and cause paralysis in those who just
been vaccinated.
• It is estimated that vaccine induced poliomyelitis is
seen in rate of 1 in 3000,000 vaccinations.

38. LIVE POLIO VACCINES –PROTECTS
SOCIETY TOO
38DWD
• The Live Polio vaccine infects multiples in the
Intestines and thus Immunizes the Individual
• Vaccines not only produces IgM and IgG in
the blood but also IgA antibodies in the
Intestines.
• Which help the gut immunity

39. LIVE VACCINE ASSOCIATED POLIO
39DWD
• On few occasions type 2 and type 3 virus may
mutate in the course of multiplication
• May lead to Vaccine associated Polio
• But very negligible

40. INJECTABLE KILLED SALK VACCINE
40DWD
• Salk Vaccine - A Killed
Vaccine. (INACTIVATED)
• Four Injections are
administered in a period of
two years,
• Administration of periodic
booster recommended.
• Most of the Western Nations
do use it.

41. VACCINATION IN
IMMUNODEFICIENT
41DWD
Only Killed viral vaccines used in
Immunodeficient persons
( SALK )

42. PULSE POLIO IMMUNISATION
42DWD
• The Indian Programme
of PULSE POLIO
Immunization is a part
of it to eradicate Polio
• Recent resurgence in UP
and Bihar is a threat to
the desired Goal.
• In spite of best efforts
thousands occur globally
in Africa and Indian
subcontinent.

43. DISEASES ASSOCIATED WITH
COXASKIE A VIRUS
43DWD
• Febrile illness with maculopapular rash.
• Upper respiratory tract infection.
• Paralytic disease.
• Meningitis & encephalitis.
• Peri and myocarditis.
• Herpangina.
• Hand, foot & mouth disease.
• Acute hemorrhagic conjunctivitis.

44. DISEASES ASSOCIATED WITH
COXASKIE A VIRUS
44DWD
• Caused by group A
Coxsackieviruses.
• Characterized by fever, sore
throat, pain on swallowing .
• Small vesicles appear on the
pharynx, Palate, uvula and
tonsils .
• Recovery is usual .

45. HAND FOOT & MOUTH DISEASE
45DWD
• Caused by group A
coxsackie viruses .
• Small papules &vesicles
develop on the buccal
mucosa, hands and feet .
• Recovery is usual .

46. DISEASES ASSOCIATED WITH
COXASKIE B VIRUS
46DWD
• Febrile illness with maculopapular rash.
• Upper respiratory tract infection.
• Paralytic disease.
• Meningitis & encephalitis.
• Peri & myocarditis.
• Pleurodynia.
• Juvenile diabetes/ pancreatitis .

47. PLEURODYNIA ( BORNHOLM
DISEASE ).
47DWD
• Caused by Coxsackie B viruses .
• Characterized by fever, headache, severe
stabbing chest pain, intensified by breathing
and movement .

48. DISEASES ASSOCIATED WITH ECHO
VIRUS
48DWD
• Febrile illness with maculopapular rash.
• Upper respiratory tract infection.
• Paralytic disease.
• Meningitis & encephalitis.
• Peri & myocarditis.

49. DWD 49
Let us be partners in Eradication of Polio