L9 Polio Virus
To which family does picornavirus belong to?
Picornaviridae
What are the 2 groups of pathogens included in Picornaviridae family? Explain them.
A. Enteroviruses
Transmitted by feco-oral route.
Multiplies in intestines, but doesn’t cause intestinal manifestations
Contains 96 serotypes, which include
- Polio virus
Composed of three serotypes
- Coxsackie virus
A&B serotypes
- Echovirus
- Parechovirus
Hepatitis A virus, is serotype 72 of enteroviruses
B. Rhinoviruses:
Transmission: respiratory route
Manifestations: common cold
What is the morphology of picornaviruses?
Small and nonenveloped, spherical in shape with icosahedral symmetry.
Contains a capsid, which composed of 60 subunits. Has a ss positive sense RNA
Inactivated by heating at 55°C. However, inactivation is prevented by the addition of magnesium
chloride.
List the resistance features of polio virus:
- Chloroform
- Bile
- Proteolytic enzymes
- Detergents
Polio virus is stable at acidic pH (pH 3). Moreover, it can survive in feces for months at 4°C, and years at
--20°C
How is polio virus destroyed?
- Heating at 55°C
- Formaldehyde
, - Chlorination
- Oxidizing disinfectants
What are the 3 serotypes of poliovirus? Explain them.
A. Serotype 1: Brunhilde and Mahoney strain
The common cause of epidemic poliomyelitis
B. Serotype 2: Lansing and MEF1 strain
Most antigenic, hence easily eradicated
C. Serotype 3: Leon and Saukett strain
No natural case reported since 2013
Name the 2 antigens found on poliovirus:
- Capsid
- Dense
What is poliomyelitis? Polio: Grey Matter
A disease caused by poliovirus, it results in the destruction of motor neurons Myelitis: Inflammation of spinal
Where does the replication of poliovirus take place? cord
Oropharyngeal membrane or intestinal mucosa
Draw a map detailing the pathogenesis of poliovirus.
Site of entery
Initial Multiplication
Feco-oral route
through Spread
ingestion Epithelial cells
of alimentary Primary Viremina
canal and Regional Lymph
Secondary
lymphatic Nodes
Virus enter Viremia
tissues that
bloodstream
contain CD155 Virus multiplies
receptor in
reticuloendothe
lial system, then
spreads to
spinal cord and
brain
How does poliovirus spread to the CNS?
To which family does picornavirus belong to?
Picornaviridae
What are the 2 groups of pathogens included in Picornaviridae family? Explain them.
A. Enteroviruses
Transmitted by feco-oral route.
Multiplies in intestines, but doesn’t cause intestinal manifestations
Contains 96 serotypes, which include
- Polio virus
Composed of three serotypes
- Coxsackie virus
A&B serotypes
- Echovirus
- Parechovirus
Hepatitis A virus, is serotype 72 of enteroviruses
B. Rhinoviruses:
Transmission: respiratory route
Manifestations: common cold
What is the morphology of picornaviruses?
Small and nonenveloped, spherical in shape with icosahedral symmetry.
Contains a capsid, which composed of 60 subunits. Has a ss positive sense RNA
Inactivated by heating at 55°C. However, inactivation is prevented by the addition of magnesium
chloride.
List the resistance features of polio virus:
- Chloroform
- Bile
- Proteolytic enzymes
- Detergents
Polio virus is stable at acidic pH (pH 3). Moreover, it can survive in feces for months at 4°C, and years at
--20°C
How is polio virus destroyed?
- Heating at 55°C
- Formaldehyde
, - Chlorination
- Oxidizing disinfectants
What are the 3 serotypes of poliovirus? Explain them.
A. Serotype 1: Brunhilde and Mahoney strain
The common cause of epidemic poliomyelitis
B. Serotype 2: Lansing and MEF1 strain
Most antigenic, hence easily eradicated
C. Serotype 3: Leon and Saukett strain
No natural case reported since 2013
Name the 2 antigens found on poliovirus:
- Capsid
- Dense
What is poliomyelitis? Polio: Grey Matter
A disease caused by poliovirus, it results in the destruction of motor neurons Myelitis: Inflammation of spinal
Where does the replication of poliovirus take place? cord
Oropharyngeal membrane or intestinal mucosa
Draw a map detailing the pathogenesis of poliovirus.
Site of entery
Initial Multiplication
Feco-oral route
through Spread
ingestion Epithelial cells
of alimentary Primary Viremina
canal and Regional Lymph
Secondary
lymphatic Nodes
Virus enter Viremia
tissues that
bloodstream
contain CD155 Virus multiplies
receptor in
reticuloendothe
lial system, then
spreads to
spinal cord and
brain
How does poliovirus spread to the CNS?
