Polio: A Disease on the Brink of Extinction Dr. Clifton FranklundAssociate Professor of Biological SciencesFerris State University

Cause History

Prevention The Future

#3

Key Points

Cause

The Polio Virus

Picornavirus

Very small

RNA genome

Three types

Humans are the only host

Key Points

Cause

The Infectious Cycle

Enteric virus

Tonsil infection

Gut infection

Viremia

Motor neurons

Shed in feces

Key Points

Cause

Result of Infections

95%

4% 1%

AsymptomaticMild SymptomsParalysis

Asymptomatic

Mild disease

Fever

Headache

Stiff neck

Paralysis is rare

Under-reporting

Key Points

History

Polio in Ancient Times

Ancient disease

Egyptian stele

Paralyzed priest

1400 BC

This virus has been around for awhile…

Key Points

History

Polio Comes to the U.S.

First diagnosed cases in the late 1800’s

1916 first large epidemic polio outbreak

Sanitation effort ineffective

Key Points

History

1916 New York Outbreak

New York City

9,000 cases

2,343 deaths

Nationally

27,000 cases

6,000 deaths

Key Points

History

Incidence in the 20th Century

Endemic in US

Seasonal polio outbreaks

July-September

Post-WWII peak

1952 peak: 57,628 cases

Key Points

History

FDR and the March of Dimes

Contracted polio at age 39

Elected president in 1932

NFIP - March of Dimes – established in 1938

Key Points

Prevention

Salk Vaccine

1953

Inactivated virus vaccine (IPV)

Required three injections

Cannot mutate

Only vaccine in USA since 1999

Key Points

Prevention

Polio Vaccine Trials

1954

Nearly two million children

Proven effective in 1955

By 1957 polio incidence was down by 90%

Key Points

Prevention

Cutter Incident

1955

Improperly prepared vaccine

Virus not inactivated

260 polio cases

192 paralyzed

Key Points

Prevention

Sabin Vaccine

1956

Attenuated vaccine (OPV)

Shed in feces

Herd immunity

Main vaccine in USA until 1999

Still main vaccine globally

Key Points

Prevention

Sabin Field Testing

1957 - 1959

Much of the US and Canada already treated

Went to Soviet Union during the Cold War

100,000,000 vaccinated by 1961

Key Points

The Future

#3Eradication of a Pathogen

Smallpox 1976

Rinderpest 2001

Polio ???

Key Points

The Future

#3The Strategy

Rotary Club 1985

Global use OPV

Goal for total eradication by 2000

Last case in USA 1979

Key Points

The Future

#3The Current Picture

Last holdouts for polio

Afghanistan

Pakistan

India

Nigeria

+

Dr. Clifton FranklundDepartment of Biological Sciences820 Campus Drive / ASC 2004Big Rapids, MI 49307franklc@ferris.edu(231) 591-2552

Questions?