Poliomyelitis Brief description and its eradication 2015 updated

1. BY- DR. RAHUL SHRIVASTAVA
BDS, MPH

2. INTRODUCTION
 Polio, or poliomyelitis, is a crippling and potentially deadly
infectious disease.
 Poliomyelitis (polio) is a highly infectious viral disease,
which mainly affects young children.
 It is caused by the poliovirus.
 The virus spreads from person to person and can invade an
infected person’s brain and spinal cord, causing paralysis
(can’t move parts of the body).
 In about 1 in 200-1000 cases, the virus escapes the
intestine, enters the bloodstream and infects the nervous
system where it causes the classic paralytic symptoms
associated with the disease.

3. GLOBAL HISTORY OF POLIO
 In the early 20th century, polio was one of the most feared diseases in
industrialized countries, paralyzing hundreds of thousands of children
every year.
 Soon after the introduction of effective vaccines in the 1950s and 1960s
however, polio was brought under control and practically eliminated as a
public health problem in these countries.
 It took somewhat longer for polio to be recognized as a major problem in
developing countries. Lameness surveys during the 1970s revealed that
the disease was also prevalent in developing countries. As a result,
during the 1970s routine immunization was introduced worldwide as part
of national immunization programmes, helping to control the disease in
many developing countries.
 In 1988, when the Global Polio Eradication Initiative began, polio
paralyzed more than 1000 children worldwide every day. Since then,
more than 2.5 billion children have been immunized against polio thanks
to the cooperation of more than 200 countries and 20 million volunteers,
backed by an international investment of more than US$ 9 billion.

4.  There are now only 3 countries that have never stopped polio
transmission and global incidence of polio cases has decreased by 99%
- in 2013, 416 cases were reported for the entire year as opposed to
over 350,000 in 1988.
 In February 2012, India, long-regarded as the nation facing the greatest
challenges to eradication, was removed from the list of polio-endemic
countries, convincing doubters that global polio eradication is feasible.
 There has also been success in eradicating certain strains of the virus;
of the three types of wild polioviruses (WPVs), the last case of type 2
was reported in 1999 and the last case of type 3 in November 2012.
 However, tackling the last 1% of polio cases has still proved to be
difficult. Conflict, political instability, hard-to-reach populations, and poor
infrastructure continue to pose challenges to eradicating the disease.
Each country offers a unique set of challenges which require local
solutions.
 Thus, in 2013 the Global Polio Eradication Initiative launched its most
comprehensive and ambitious plan for completely eradicating polio. It is
a 5 year all-encompassing strategic plan that clearly outlines measures
for eliminating polio in its last strongholds and for maintaining a polio-

5.  1580–1350 BC
An Egyptian stele portrays a
priest with a withered leg,
suggesting that polio has
existed for thousands of
years.

6. SIGN & SYMPTOMS
 Most people who get infected with poliovirus (about 72 out
of 100) will not have any visible symptoms.
 About 1 out of 4 people with poliovirus infection will have flu-
like symptoms that may include—
1. Sore throat
2. Fever
3. Tiredness
4. Nausea
5. Headache
6. Stomach pain
 These symptoms usually last 2 to 5 days then go away on
their own.

7.  Initial symptoms of polio include fever, fatigue, headache,
vomiting, stiffness in the neck, and pain in the limbs.
 In a small proportion of cases, the disease causes paralysis,
which is often permanent.
 There is no cure for polio, it can only be prevented by
immunization.

8.  A smaller proportion of people with poliovirus infection will
develop other more serious symptoms that affect the brain
and spinal cord:
1. Paresthesia (feeling of pins and needles in the legs)
2. Meningitis (infection of the covering of the spinal cord
and/or brain) occurs in about 1 out of 25 people with
poliovirus infection
3. Paralysis (can’t move parts of the body) or weakness in the
arms, legs, or both, occurs in about 1 out of 200 people with
poliovirus infection
 Paralysis is the most severe symptom associated with polio
because it can lead to permanent disability and death.
Between 2 and 10 out of 100 people who have paralysis
from poliovirus infection die because the virus affects the
muscles that help them breathe.

9. WHAT’S POST-POLIO SYNDROME?
 Even children who seem to fully recover can develop new
muscle pain, weakness, or paralysis as adults, 15 to 40
years later. This is called post-polio syndrome.
 Note: "poliomyelitis" (or "polio" for short) is defined as the
paralytic disease. So only people with the paralytic infection
are considered to have the disease.

10. TRANSMISSION
 Poliovirus only infects humans.
 It is very contagious and spreads through person-to-person
contact.
 The virus lives in an infected person’s throat and intestines.
 It enters the body through the mouth and spreads through
contact with the feces (poop) of an infected person and,
though less common, through droplets from a sneeze or
cough.
 You can get infected with poliovirus if you have feces on
your hands and you touch your mouth.

11.  Also, you can get infected if you put in your mouth objects
like toys that are contaminated with feces (poop).
 An infected person may spread the virus to others
immediately before and about 1 to 2 weeks after symptoms
appear.
 The virus can live in an infected person’s feces for many
weeks.
 It can contaminate food and water in unsanitary conditions.
 People who don’t have symptoms can still pass the virus to
others and make them sick.

12. PREVENTION
 Polio vaccine protects children by preparing their bodies to
fight the polio virus.
 Almost all children (99 children out of 100) who get all the
recommended doses of vaccine will be protected from polio.
 There are two types of vaccine that can prevent polio:
1. Inactivated poliovirus vaccine (IPV)
2. Oral poliovirus vaccine (OPV).
 Only IPV has been used in the United States since 2000;
OPV is still used throughout much of the world.

13. HISTORY OF POLIO - ERADICATION
 Polio is a crippling and potentially fatal infectious disease.
 There is no cure, but there are safe and effective vaccines.
 Therefore, the strategy to eradicate polio is based on
preventing infection by immunizing every child to stop
transmission and ultimately make the world polio free.
 In 1988, the World Health Assembly adopted a resolution for
the worldwide eradication of polio.
 It marked the launch of the Global Polio Eradication Initiative
(GPEI), spearheaded by national governments, CDC,
Rotary International, WHO, and UNICEF, with substantial
support from the Bill & Melinda Gates Foundation.

14. CURRENT SCENARIO

23. EXISTING POLIO VACCINE
 There are two types of poliovirus vaccines in current use.
1. Killed Salk vaccine, which consists of chemically
inactivated wild poliovirus.
 As there are three serotypes of poliovirus, the Salk vaccine
contains a representative amount of each serotype.
 The Salk vaccine is administered intramuscularly, and being
a killed vaccine, predominantly induces systemic antibodies.
 These protect against disease by preventing spread from
the gut to the nervous system.
 However, the Salk vaccine does not induce strong mucosal
immunity, so poliovirus can replicate freely in the intestines
of even vaccinated individuals, and the infection can then be
spread to unvaccinated contacts.

24. 2. Sabin vaccine, which is a live-attenuated vaccine.
 It contains weakened vaccine strains of each of the three
serotypes. The Sabin vaccine is given orally, replicates in
the intestines of vaccinees, induces both mucosal and
systemic immunity, and protects against infection of the
intestine by ingested virulent poliovirus.
 The Sabin vaccine also has drawbacks; notably, it can
revert to a virulent form, and there are documented cases
of circulating revertant Sabin poliovirus causing outbreaks
of disease in areas from which the natural virus had been
previously eradicated.
 The Sabin vaccine has been used to eradicate poliovirus
from most of the globe.

25.  In these areas of Africa and the Indian subcontinent,
children who have received multiple vaccinations with the
Sabin vaccine still develop incomplete immunity to poliovirus
and can suffer from paralysis.
 In these places, intestinal parasites and other infections are
probably activating the innate immune system which
interferes with the replication of the Sabin vaccine strains in
the gut, thus preventing the development of immunity to
poliovirus.

26. GLOBAL VACCINE ACHIEVEMENT &
COLLABORATION
 Collaborating with the Netherlands Vaccine Institute (NVI/RIVM), GV
have tested their cGMP manufactured Salk vaccine in conjunction with
the GVI adjuvant.
 In mice, the adjuvant improved the level of systemic antibodies by a
factor of 4-8 for each of the three serotypes in the Salk vaccine. While
the Salk vaccine alone did not induce cellular immunity, immune cells
were induced in the presence of the adjuvant.
 Finally, intestinal IgA and IgG, indicative of mucosal immunity, were
induced with the adjuvant, whereas these were not detected in mice
receiving Salk alone.
 Scientists at NVI/RIVM have conducted a rat potency test with the Salk
vaccine and the Salk vaccine plus adjuvant.
 This test is the international standard for determining the potency of
each batch of Salk vaccine. With the adjuvant, comparable levels of
potency were achieved with 1/7 the amount of vaccine.
 This dose sparing effect was highly significant. An even more impressive
dose sparing effect was found in this test with inactivated Sabin vaccine.

27. WARNING : POLIO!!!
 Polio spreads from person to person invading the brain and
spinal cord and causing paralysis (inability to move).
 Because polio has no cure, vaccination is the best way to
protect people and is the only way to stop the disease from
spreading.
 The spread of polio has never stopped in Afghanistan,
Nigeria, and Pakistan.
 After the spread of the polio virus had previously been
stopped, it has been reintroduced and continues to spread
in the Horn of Africa, Cameroon, and Syria.

28. ERADICATION PROGRAMME

33. CDC POLIO ERADICATION ACTIVITIES
 An in-depth review of priority countries’ polio eradication plans to assess
program gaps and training needs, and elaboration of plans for CDC’s
engagement in those countries.
 Publication of several joint World Health Organization Weekly
Epidemiologic Record/CDC Morbidity and Mortality Weekly Reports
(MMWR) highlighting polio eradication progress related
to Nigeria, Afghanistan and Pakistan, risk assessment for polio
outbreaks, possible eradication of wild poliovirus type 3, polio-free
certification in SEARO, and progress towards worldwide eradication.
 Collaboration with GPEI partners on detailed country-plans for expanded
technical and management support, including assistance with outbreak
responses, surveillance reviews, vaccination campaign planning and
monitoring, and data management.
 The development of indicators for monitoring polio vaccination campaign
performance in the areas of planning, implementation, and evaluation
 Review of WHO proposed outbreak response protocols for all polio-
affected and at risk countries.

34. GLOBALLY ACHIEVED SUCCESS
 Polio incidence has dropped more than 99 percent since the
launch of global polio eradication efforts in 1988.
 According to global polio surveillance data from July 15, 2015, 33
cases have been reported in 2015: 28 from Pakistan and 5 from
Afghanistan.
 While no polio cases have been detected in India for more than
three years, poliovirus transmission is ongoing in the three
endemic countries – Afghanistan, Nigeria, and Pakistan. GPEI’s
Independent Monitoring Board considers Nigeria and Pakistan to
be the greatest challenges for eradicating polio.
 On May 5, 2014, after receiving advice from an Emergency
Committee of independent experts and in order to protect
progress toward eradication, WHO Director- General Margaret
Chan declared the recent international spread of wild poliovirus a
“public health emergency of international concern,” and issued
Temporary Recommendations under the International Health
Regulations (2005) to prevent further spread of the disease.

35. ACHIEVEMENT OF PUBLIC HEALTH WORKERS

36. REFERENCES
 http://www.who.int/topics/poliomyelitis/en/
 http://www.cdc.gov/polio/about/index.htm
 http://www.polioeradication.org/Dataandmonitoring/Poliothisweek.aspx
 http://www.thehindu.com/news/cities/bangalore/pulse-polio-
immunisation-drive-on-jan-18-feb-22/article6788724.ece
 http://www.globalvaccines.org/content/polio+vaccine+program/19613#E
xisting Polio Vaccines