What is Poliomyelitis
Poliomyelitis is caused by the Poliovirus
Poliovirus= form of Enterovirus that affects
Enteroviruses: spread primarily through the
fecal-oral route (contact with feces somehow)
Children at highest risk.
Symptoms appear similar to common cold:
difficult to diagnose early on.
History Of Polio
Ancient Egypt England- Michael Underwood- 1789
“debility of lower extremities”>”HeineMedin disease”>”infantile paralysis”
Due to propensity to more commonly affect
Causes & Transmission
More prevalent in warmer climates/ summer
Transmitted through fecal-oral route.
Most cases- Parent-to-Child due to close proximity,
also unsanitary water.
Temporarily inhabits gastrointestinal tract, due to how
Highly contagious during incubation period (6-20
Effects of Transmission
o 95% cases- Asymptomatic
o 4%-8%- non-paralytic aseptic meningitis
o 1%- Paralytic Polio: 3 types
o Spinal (PV1), Bulbospinal (PV2), Bulbar (PV3)
o Spinal- most closely associated w/ paralysis
o 1/200 cases paralytic
o 1/1,000 infant cases & 1/75 adult cases of polio.
Outbreaks & Outcomes
First global outbreaks: 1900’s- caused by increase
Previous - common to contract Poliovirus as child
but not see side-effects - latent immunization
through constant exposure created immunity
Increased populations allowed greater spread of
Outbreaks & Outcomes Cont’d.
Infection age rose:
6 months- 4 yrs > 5-9 yrs.
Greater amount of paralytic polio due to age.
No prevalent hereditary links/suseptibility
differences = difficult to diagnose
No vaccine developed
Wreaked havoc for 1st half of 20th Century
Race for a Cure
Increased Polio outbreaks forced need for a cure.
President Roosevelt- contracted Paralytic polio in
mid 20’s. Founds National Foundation for Infantile
Paralysis in 1938.
World War II = on hold.
1952- greatest U.S. outbreak on record
58,000 reported cases
22,000 paralyzed & 4,000 killed.
1955: Salk & Sabin discover vaccines
Effects of Vaccination
Vaccination reported near 100% immunity
The WHO (World Health Organization) set
out for global eradication in 1988.
350,000 cases in 1988 > 1,310 cases in 2007
Job not done
Still exists in India, Nigeria, Afghanistan,
Where is the Future of
• Difficulty in eradication caused by:
• Re-infection from unvaccinated
countries (25 from 2003-2005).
• Civil War in Countries
• Religious beliefs.
• Threat of future endemic as virus still
exists as long as polio exists anywhere in
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