Transcript POLIOMYELITIS

Poliomyelitis and Post Polio
Syndrome
Mazloumi MD
Qaem,s Hospital
What is Poliomyelitis?
• polio= gray matter
• Myelitis= inflammation of the spinal cord
• This disease result in the destruction of
motor neurons caused by the poliovirus.
• Polio is causes by a virus that attacks the
nerve cells of the brain & spinal cord
although not all infections result in sever
injuries and paralysis.
POLIOMYELITIS
• “Picornavirus”
• 3 types: Poliovirus
1,2,3
• Ingested, spread by
faeco-oral route:
Commoner in areas of
poor sanitation
• Infants protected by
maternal antibodies
History
• Associated with man since
ancient times
• Egyptian hieroglyph indicates
presence since 1400 BC
• 1840 - Heinle characterizes
poliomyelitis
• Poliomyelitis – “grey marrow”
in Greek
• 1954 - Salk vaccine
• 1960 - Sabin vaccine
• 1991 – Molla produces polio in
vitro from virus RNA
• 2002 – completele synthetic
production
Polio Eradication:
Status in 1988
Polio Eradication:
Status in 1998
Epidemiology
• “Silent circulation”
Many hundreds may
be infected prior to the
development of a
single case of paralysis
• WHO considers a
single confirmed case
of polio in an area of
low occurrence an
epidemic
How is polio transmitted?
• Poliovirus is transmitted through both oral
and fical routes with implantation and
replication occurring in either the
orapgaryngeal and or in the intestine of
mucosa. Polio cases are most infected for 710 days before and after clinical symptoms
begin.
The unique stages of
infection and pathogenesis
of poliomyelitis.
Poliovirus, an “Enterovirus” has an
icosahedral capsid shell that protects
it from digestion.
GI Tract
 Blood
 Cord
 CNS
Paralysis of motor
neurons
Provocative Poliomyelitis
• Provocative poliomyelitis occurs when a
person having polio virus circulating in
blood (viraemia) receives any intramuscular injection.
• Reason is increased susceptibility of the
relevant anterior horn cells resulting in
settling of the circulating polio virus there
and consequential paralysis.
What are the symptoms?
• Many include fever, pharyngitis, headache,
anorexia, nausea, and vomiting. Illness may
progress to aseptic meningitis and
menigoencephalitis in 1% to 4% of patients.
These patients develop a higher fever,
myalia and sever headache with stiffness of
the neck and back.
Clinical Pattern of Polio
Virus travels through blood and the
nerves
… And each place in the
cord that nerve cells are
destroyed causes paralysis
of that part of the body
controlled by those motor
neurons.
POLIO ATTACKS MOTOR
NEURONES
Poliomyelitis:Clinical Features
• In 1% of cases virus
invades CNS:
• Multiples and destroys
anterior horn cells.
• In severe cases,
poliovirus may attacks
motor neurones in
brainstem, leading to
difficulty in swallowing,
speaking and breathing
Equanous deformity
• Tibialis anterior
muscle paralysis
(most common)
• Heel elevated
• Toe gait
• Achill tendon
contracture
Calcaneous deformity
• Gastrosoleous muscle
paralysis
(Cavous foot)
Varous deformity
• Peroneal muscle
paralysis ,associate
with equanuse
deformity
(paralytic equano
varous )
Planovalgus deformity
• Tibialis posterior
paralysis
( Flat foot )
Paralytic Scoliosis
• Paravertebral
muscleparalysis
( Pelvic title )
Knee deformities
• Hamstring muscle
paralysis(Geno
recurvatum )
• Quadriceps muscle
paralysis ( knee
flection contracture )
Treatment
• Intensive
physiotherapy
Treatment
Orthosis
treatment
tenotomy
osteotomy
arthrodesis
Tendon
transfer
Soft tisue
release
Inactivated Vaccine
•
•
•
•
Immunity to Poliovirus 1,2,3
Safe, effective
Jonas Salk
Injection
No gastrointestinal immunity: Risks of
continued circulation of virus in endemic areas
• Expensive
Live Vaccine
– Live attenuated oral vaccine (Sabin, 1961):
– Risks of viral mutation, leading to potential
regain of virulence:
– Excretion of live virus thru’ faeces
– Live vaccine cheaper, and suitable for mass
vaccination programmes
Poliomyelitis:Current Status
• Eradicated from
developed world in 1960s
• Remains endemic in 7
countries
• Eradication plan by
WHO by year 2000: not
yet achieved, but
progress is being made