Transcript Global Polio Eradication: history, achievements & challenges Omar Khan, MD MHS Overview         History & Relevance Basics of Polio Vaccination Eradication plan Achievements Challenges Personal experiences A polio cartoon.

Global Polio Eradication:
history, achievements & challenges
Omar Khan, MD MHS
Overview
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History & Relevance
Basics of Polio
Vaccination
Eradication plan
Achievements
Challenges
Personal experiences
A polio cartoon
History & Relevance
The more definitions change, the more they stay the
same: Polio defined in 1895 and 2005
History & Relevance
Poliomyelitis:
Acute inflammation of the anterior horns of the gray
matter of the spinal cord, leading to a destruction of the
large multipolar cells of these horns. It is most common
in children, coming on during the period of the first
dentition and producing a paralysis of certain muscle
groups or of an entire limb.
Gould’s Illustrated Medical Dictionary, 1895
History & Relevance
Poliomyelitis:
An inflammatory process involving the gray matter of
the cord. An acute infectious disease caused by the
poliomyelitis virus and marked by fever, pains, and
gastro-enteric disturbances, followed by a flaccid
paralysis of one or more muscular groups, and later by
atrophy.
Stedman’s, 2005
History & Relevance
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In 1916, New York City experienced the first large epidemic of
polio, with over 9,000 cases and 2,343 deaths. The 1916 toll
nationwide was 27,000 cases and 6,000 deaths. Epidemics
worsened during the century: in 1952, a record 57,628 cases of
polio were reported in the United States.
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Polio (also called infantile paralysis) was most often associated
with children, but it affected teens and grown-ups as well. Between
1949 and 1954, 35 percent of those who contracted polio were
adults.
Sign from a home
in Atlanta where an
infant contracted
polio, 1941
History & Relevance
1953: Pool in Elmira, New York, with sign
indicating it is closed due to polio
History & Relevance
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The first known polio outbreak in the United States?
History & Relevance
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Vermont, 1894:
“Early in the summer just passed, physicians in certain parts of
Rutland County, Vermont, noticed that an acute nervous disease
which was almost invariably attended with some paralysis, was
epidemic … and a general feeling of uneasiness … was
perceptible among the people in regard to the ‘new disease’ that
was affecting the children.”
-- Dr. C. S. Caverly, reporting on the first epidemic outbreak of polio
in the United States, 1894
History & Relevance
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Polio affected events,
lives, and people
History & Relevance
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Throughout most of the 20th century, hospitals operated under
strict and orderly patient regimens. Epidemic conditions, combined
with the lack of a cure for polio, heightened everyone’s anxiety.
During a 1934 epidemic in Los Angeles, 5 percent of doctors and
11 percent of nurses who treated polio patients contracted the
disease.
History & Relevance
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What’s this?
History & Relevance
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Iron lung ward at the Massachusetts General Hospital
History & Relevance
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The last cases of wild (naturally occurring) polio in the United
States were in 1979 in four states, among Amish residents who
had refused vaccination.
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2006 is the 50th anniversary of the announcement that Dr. Jonas
Salk had developed a polio vaccine: Smithsonian exhibit (below)
Evidence of sporadic epidemics of polio predate recorded history.
1789, British physician Michael Underwood provides first clinical description of the disease.
1840, Jacob Heine describes the clinical features of the disease as well as its involvement of
the spinal cord.
1894, first outbreak of polio in epidemic form in the U.S. occurs in Vermont, with 132 cases.
1908, Karl Landsteiner and Erwin Popper identify a virus as the cause of polio by transmitting the
disease to a monkey.
1916, large epidemic of polio within the United States.
1921, FDR contracts polio at age 39. Although he is open about having had polio, he conceals the
extent of his disability.
1929, Philip Drinker and Louis Shaw develop the “iron lung” to aid respiration.
1930s, two strains of the poliovirus are discovered (later it was determined that there were three).
1931, scientists create the first filter able to trap viruses.
1933, FDR inaugurated president of the United States.
1935, Maurice Brodie and John Kolmer test polio vaccines, with disastrous results.
1938, FDR founds the National Foundation for Infantile Paralysis, known today as the March of Dimes.
1940s, Sister Kenny, an Australian nurse, comes to the U.S. to promote her new treatment for polio,
using warm compresses to relax painful, contracting muscles and massage for rehabilitation.
1947 - 50, Dr. Jonas Salk is recruited by the University of Pittsburgh to develop a virus research
program.
1953, Salk and his associates develop a potentially safe, inactivated (killed), injected polio vaccine.
1954, nearly two million children participate in the field trials.
1955, news of the success of the trials is announced by Dr. Thomas Francis in a formal press conference at
Ann Arbor, Michigan, on April 12, the tenth anniversary of FDR's death. The news was broadcast both on
television and radio, and church bells rang in cities around the United States.
1955 - 57, incidence of polio in the U.S. falls by 85 - 90%.
1957 - 59, mass clinical trials of Albert Sabin's live, attenuated vaccine in Russia.
1962, the Salk vaccine replaced by the Sabin vaccine for most purposes because it is easier to administer
and less expensive.
1968, passage of the Architectural Barriers Act, requiring that all federally financed buildings be accessible to
people with disabilities.
1979, last case of polio caused by “wild” virus in U.S.; last case of smallpox in the world.
1980s, post-polio syndrome identified by physicians and people who had polio.
1980, the first National Immunization Day for polio held in Brazil.
1981, poliovirus genome sequence published.
1985, Rotary International launches PolioPlus program.
1988, Rotary International, PanAmerican Health Organization, World Health Organization, Centers for
Disease Control, UNICEF begin international campaign to stop transmission of polio everywhere in the world.
1990, Passage of the Americans with Disabilitites Act (ADA), providing broad legal protections for people with
disabilities.
1999, inactivated polio vaccine replaces oral polio vaccince as recommended method of polio immunization
in the United States.
A bit about polio: basics
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“If the ability to replicate is one of life’s attributes,
then polio is a chemical with a life cycle…. Viruses
are ‘living’ chemicals. They have structural
uniformity, like crystals, but can only self-replicate
inside living cells. Poliovirus is made up of carbon,
hydrogen, nitrogen, oxygen, phosphorus and
sulphur; from these elements, the virus forms its
RNA (ribonucleic acid) genes, and its protective
protein coat.”
-- Jeronimo Cello, Aniko V. Paul, Eckard Wimmer,
creators of the synthesized poliovirus, 2002
Poliovirus
EMs
A bit about polio: basics
Life cycle of poliovirus
A bit about polio
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Affects mostly children under 3 (50% of all cases)
Majority asymptomatic
About 10% will get ‘minor illness’: fever, nausea, vomiting
0.5 -1% infections leads to irreversible paralysis (AFP), with
maximum effect taking place in 3-4 days
Legs affected more than arms; paralysis of respiratory muscles is
life-threatening
Humans are the only reservoir for the poliovirus. The virus does
not naturally reproduce in any other species.
Transmission is usually fecal-oral (oral-oral is possible)
Virus sheds from stool for 4-6 weeks
No treatment; deformity and handicap can be minimized with early
PT
A bit about (post) polio
• Post-polio syndrome (PPS): a disorder of the nervous system
that appears in people who experienced paralytic poliomyelitis,
usually 15 – 40 years after the original illness.
• The main symptoms are new progressive muscle weakness, severe
fatigue and pain in muscles and joints. Less common symptoms
include muscle atrophy, breathing and swallowing difficulties, sleep
disorders, and cold intolerance.
• Exact mechanism by which PPS causes fatigue, pain, and new
weakness is not completely understood.
A bit about (post) polio
• Possibly related to the gradual loss of individual nerve cells, and
subsequent loss of nerve transmission to these fibers.
•After the original polio infection, surviving nerve cells sprout extra
branches that re-attach to muscle fibers.
•Although the the muscle fibers occasionally work as well as before,
some suggest that PPS develops because these extra axonal sprouts
cannot “hold” forever, but instead get weaker over time due to
“overexertion”.
Eradicating polio?
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In 1988, the World Health Assembly (WHA) the
annual meeting of the ministers of health of all
Member States of the World Health
Organization, voted to launch a global goal to
eradicate polio.
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As a result, the largest public health effort to
date was put together: The Global Polio
Eradication Initiative (GPEI).
Vaccination: the key intervention in the GPEI
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2 ways to get immunity: infection or
immunization
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The live attenuated oral polio vaccine (OPV)
was developed by Dr. Albert Sabin in 1961. The
inactivated (killed) polio vaccine (IPV), was
developed in 1955 by Dr. Jonas Salk and is an
injected vaccine.
Vaccination: Salk vs Sabin
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OPV (Sabin): provides immunity to all 3 strains of polio.
Induces humoral immunity systemically as well as local
GI mucosal immunity (which limits transmission during
outbreaks).
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IPV (Salk): Also induces humoral immunity via
antibodies. However, it induces very low levels of
immunity to poliovirus locally, inside the gut. As a
result, it provides individual protection against polio
paralysis but, unlike OPV, cannot prevent the spread of
wild polio virus.
Vaccination: Salk vs Sabin
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IPV cannot cause vaccine-associated paralytic polio
(VAPP).
OPV can, but at a rate of 1/2.5 million doses
US started OPV in 1961, switched to IPV in 1999
OPV benefits for public health programs are:
– easy to give (drops)
– cheap (8 cents a dose) vs IPV (almost $1/dose with syringe,
not including cost of health worker)
– short term shedding of live virus from immunized kids will likely
immunize others via contact
– Interrupts transmission during outbreaks due to mucosal GI
immunity
Vaccination trend in the US
25000
Inactivated vaccine
Cases
20000
15000
Live oral vaccine
10000
Last indigenous case
5000
0
1950
1956
1962
1968
1974
1980
1986
1992
1998
Vaccination trend in the US
VAPP Cases
non-VAPP
OPV doses in millions
10
9
25
IPV-OPV
8
7
20
All-IPV
6
15
5
4
10
3
2
5
1
19
90
19
91
19
92
19
93
19
94
19
95
19
96
19
97
19
98
19
99
20
00
20
01
20
02
20
03
0
0
Vaccination schedule in the US
Age
2 months
4 months
6-18 months
4-6 years
Vaccine
IPV
IPV
IPV
IPV
Eradicating polio?
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When GPEI was launched, wild poliovirus was
endemic in more than 125 countries on five
continents, paralyzing more than 1000 children
every day
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Since 1988, some two billion children around
the world have been immunized against polio
Eradicating polio: funds
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Funding: $3 billion to date
The major players in the GPEI are the World
Health Organization (WHO), Rotary
International, the US Centers for Disease
Control and Prevention (CDC) and UNICEF.
In 1987, Rotary international launched a $120M
campaign for polio
The campaign raised $247M in 1 year
Eradicating polio: who does what
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WHO: overall coordination of NIDs, SNIDs, mop-up
campaigns as well as technical assistance and strategy
Rotary: advocacy and funding at the global and local
country levels
CDC: technical expertise, polio surveillance, epi
investgations
UNICEF: field-based support for polio vaccination as
part of its own EPI (Expanded Programme on
Imunizations) initiative
Eradicating polio: the plan
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Interrupting transmission: 2004-5
Certifying polio-free regions 2006-8
Cessation of OPV 2006-8
Mainstreaming the GPEI 2009+
Eradicating polio: the reality
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Interrupting transmission: 2004-5
– High infant immunization coverage with four doses of oral polio
vaccine (OPV) in the first year of life - routine immunization
with OPV
– National immunization days (NIDs) to provide supplementary
doses of oral polio vaccine to all children under five years of
age
– Surveillance for wild poliovirus through reporting and
laboratory testing of all cases of acute flaccid paralysis (floppy)
among children under fifteen years of age
– Targeted "mop-up" campaigns once wild poliovirus transmission
is limited to a specific focal area
Eradicating polio: the reality
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Certifying polio-free regions 2006-8:
– Achieving certification-standard surveillance
– Ensuring access to a WHO-accredited laboratory
– Ensuring containment of wild polioviruses and Vaccine Derived
Poliovirus (VDPVs)
– Completing the certification process (regulatory in nature)
Eradicating polio: the reality
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Cessation of OPV 2006-8
– Polio outbreaks caused by vaccine-derived polioviruses (VDPVs)
have shown that continuing the use of oral polio vaccine (OPV)
for routine immunization could compromise the goal of
eradicating all paralytic disease due to circulating polioviruses.
– Therefore to minimize the risks associated with the use of oral
polio vaccine it has been recognized that the world must stop
the routine use of this vaccine as soon as possible after global
certification, while surveillance sensitivity and population
immunity are high.
Eradicating polio: the reality
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Mainstreaming the GPEI 2009+
– Minimize the perception of this being a ‘vertical program’
– GPEI has supported the delivery of other health services, such
as the distribution of vitamin A supplementation, integrated
disease surveillance, supporting routine immunization services,
and supporting the implementation of activities of the Global
Alliance for Vaccines and Immunization (GAVI)
– Transition polio human resources and infrastructure for the use
for other disease control programs
Eradicating polio: achievements
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By end-2003 (I.e., in 15 years), the no. of countries
with endemic polio had shrunk to 6: Afghanistan,
Egypt, India, Pakistan, Niger, Nigeria.
The early leader was Latin America: PAHO (the
regional WHO office) committed in 1985 to
eradicate polio from the Americas
The last case in the Americas was in 1991: a 3-year
old boy (Luis Tenorio) in Peru
Eradicating polio: achievements
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In 1995, a Global Commission for Polio Eradication was
formed, and prepared regional plans which gave rise to
GPEI’s current structure
In 1995, Afghanistan allowed its 3rd national 1-day
ceasefire for immunizations to happen
Also in 1995, India conducted its first National
Immunization Day (NID), vaccinating a historic 87M
kids
The last case in China was in 1996; the last case in the
Western Pacific region (the 2nd to be polio-free) was
1997 (Cambodia).
Eradicating polio: achievements
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1999: more African countries, e.g. Angola and Congo,
agree to cease-fires for polio campaigns.
2000: low of 719 cases
2001: low of 483 cases
2002: blip of 1919 cases, in only 7 countries; 98% of
these were in India, Pakistan and Niger
2002: EURO becomes the 3rd region to be polio-free
2006: 296 cases so far
Eradicating polio:
achievements
Eradicating polio:
problems
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In Nigeria, some states
suspended polio immunization
in August 2003, following
concerns regarding the safety
of the polio vaccine
A new outbreak occurred,
originating in one of those
states, re-infecting previously
polio-free areas within Nigeria
Eight previously polio-free
countries across Africa were reinfected as well
Eradicating polio: problems
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Somalia is the only country in the world with a
geographically expanding polio outbreak.
Plagued by ongoing conflict, insecurity, lack of a
health infrastructure and low rates of population
immunity, it is at the top of the Global Polio
Eradication Initiative's list of acute challenges.
Eradicating polio: problems
Increasing money being spent on smaller
number of cases
 Donor fatigue
 Health worker fatigue and frustration:
when will it be over?
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Polio figures today (if today is May 2, ‘06)
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Nigeria (endemic)
India (endemic)
Somalia (importation)
Afghanistan (endemic)
Niger (importation)
Pakistan (endemic)
Indonesia (importation)
Ethiopia (importation)
Yemen (importation)
Bangladesh (importation)
Nepal (importation)
236
22
20
6
3
2
2
2
1
1
1
Map
Notes from the field
Joined Pakistan and
Afghanistan team in Nov. 05
for NIDs
 Rapidly learned why 80% of cases in these 2
countries are in about 3 provinces
 ‘Social determinants of health’ demonstrated daily:
cultural barriers; mistrust; resentment from
Afghan/Soviet war; inequity between these
impoverished areas and the rich cities
 Unpredictable barriers: the largest natural disaster
to his South Asia (earthquake killing 80,000) had
just hit
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More on the resentment: mass graves near
Pak-Afghan border
The polio vaccination team vehicles
Getting there isn’t half the problem;
it’s most of it
Polio reservoirs
Sewage
Drinking water
Sewage
Polio markings: an inexact science
Finding a case (1 of 19 in 2005)
Vaccination campaigns:
Village in Pakistan
Refugee camp in Afghanistan
Vaccination campaigns
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Empty canisters of
vaccine to tally up
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List of potential polio
cases
Vaccinated!
Vaccinated children’s 5th fingernail is marked
with purple indelible marker
Polio in comic book form:
http://www.pbs.org/wgbh/aso/ontheedge/polio/
Links & References
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WHO site /GPEI:
www.polioeradication.org
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Polio Case Count:
http://www.polioeradication.org/casecount.asp
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CDC: www.cdc.gov/nip
Acknowledgement
With thanks to David Heymann, Tim Brookes, and the American
Public Health Association (APHA)