EPIDEMIOLOGY OF POLIO MYELITIS AND POLIO ERADICATION PROGRAMME IN INDIA by sammyc2007

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									  EPIDEMIOLOGY OF POLIO MYELITIS
      AND POLIO ERADICATION
       PROGRAMME IN INDIA

                   DR.I.SELVARAJ, I.R.M.S
B.Sc.,M.B.B.S.,(M.D COMMUNITY MEDICINE) D.P.H., D.I.H.,P.G.C.H&FW(NIHFW,NEW DELHI)

               Sr.D.M.O (ON STUDY LEAVE)
        INDIAN RAILWAY MEDICAL SERVICE
•THE AMERICAS WERE CERTIFIED POLIO-FREE
IN 1994. (36 COUNTRIES)
• THE WESTERN PACIFIC WAS CERTIFIED
POLIO-FREE IN 2000. (37 COUNTRIES AND
AREAS INCLUDING CHINA)
•EUROPE, COMPOSED OF 51 COUNTRIES, WAS
CERTIFIED POLIO-FREE IN JUNE 2002. (51
COUNTRIES)
• WITH ONLY SIX POLIO ENDEMIC COUNTRIES
LEFT IN THE WORLD, POLIO TRANSMISSION
COULD BE STOPPED BY END 2005. THE WORLD
COULD THEN BE CERTIFIED POLIO-FREE BY
END-2008.
HISTORY
1789 - British physician Michael Underwood
provides the first clinical description of polio,
referring to it as "debility of the lower
extremities."
1840 - German physician Jacob von Heine
publishes a 78-page monograph in 1840 which
not only describes the clinical features of the
disease, but also notes that its symptoms
suggest the involvement of the spinal cord.
1908- Austrian physicians Karl Landsteiner
and Erwin Popper make the first hypothesis
that polio may be caused by a virus.
In 1908, Karl Landsteiner & Erwin Popper discovered a
filterable agent as the cause of poliomyelitis. An extract of
medula from a fatal human case was injected
intraperitoneally in monkeys. He worked then at the Pasteur
Institute, because no monkeys were available in the
University of Vienna. The lesions that appeared were
indistinguishable from those found in humans.
They could not pass the disease monkey to monkey, but
Simon Flexner & Paul Lewis managed this and found
antibodies. Arnold Netter & Constantin Levaditti found
antibodies in human convalescents in 1908. Levaditti &
Landsteiner demonstrated neutralizing antibodies in
monkey serum against active virus. Frank Mcfarland
Burnet & Jean MacNamara en 1931 demonstrated
serotypes.
In 1936, Albert Sabin & Peter Olitsky
cultured poliovirus in embryonic nervous
cells. In 1949, John Enders, Thomas
Weller & Frederick C. Robbins grew the
virus in muscle cells (fibroblasts) human
embryonic skin cells, connective tissue
cells, intestine and nervous cells, winning
the Nobel prize in 1954. The important
production point is that the virus grows in
nonnervous cells.
Sabin, Albert: (1906-93) Pioneering researcher on viruses and viral diseases
who developed the oral live-virus vaccine against polio. Sabin's vaccine came
to be preferred over the alternative killed-virus vaccine developed by his bitter
rival Dr. Jonas Salk. The Sabin vaccine contains harmless attenuated polio
virus.
Dr. Sabin first showed that polio virus could grow in human nerve tissue
outside the human body. Through research on monkeys he discovered how the
polio virus entered the human body. It had been widely thought that the virus
entered through the respiratory tract. Sabin proved that the virus first invaded
the digestive tract and later attacked nerve tissue.
Albert Bruce Sabin was born in Bialystok, Poland. He immigrated with his
family to the US in 1921. He graduated from New York University medical
school. He trained in pathology, surgery and internal medicine at Bellevue
Hospital in New York and spent a year in research at the Lister Institute in
London. In 1935 he returned to New York to join the Rockefeller Institute and
then in 1939 moved to the University of Cincinnati and its Children's Hospital
Research Foundation.
               AGENT: POLIO VIRUS

The virion consists of a single strand of RNA
containing genetic information and a protein
coat. Humans are its only natural host.
 - The poliovirus is a member of a larger family
known as Picornaviruses, which also includes
rhinoviruses (such as influenza) and the hepatitis A
virus.
 - Polio belongs to the enterovirus subgroup, made
up of over 70 viruses that infect the intestines.
 - It is one of the smallest RNA viruses, measuring
around 25 nm in diameter.
                   EPIDEMIOLOGY

•   AGENT: POLIOVIRUS
•   TYPE : THREE SERO TYPES(TYPE-1,TYPE-2,TYPE-3)
•   RESERVOIR: MAN
•   INFECTIOUS MATERIAL: FAECES, ORO-PHARYNGEAL
    SECRETIONS
•   INCUBATION PERIOD: 7 TO 14 DAYS( 3- 35 DAYS)
•   PERIOD OF COMMUNICABILITY: 7 TO 10 DAYS
•   HOST : AGE : 6 MONTHS TO 3 YEARS
•   ENVIRONMENT : RAINY SEASON (JUNE TO SEPTEMBER)
•   MODE OF TRANSMISSION: FAECO – ORAL ROUTE,
    DROPLET INFECTION
Group:     Group IV ((+)ssRNA)


Family:
           Picornaviridae


Genus:     Enterovirus


Species:   Poliovirus
 Left: Picture of poliovirus.
The poliovirus is extremely
         small, about 50 nm            Right: Cross-section of the poliovirus
(nanometer = one-billionth          showing the RNA, capsid, and nerve cell
    of a meter) Courtesy of     receptors Illustration courtesy of Link Studio
  David Belnap and James
                       Hogle
•Inapperent(sub-clinical) Infection: this occurs
approximately in 95 per cent of poliovirus infection. There
are no presenting symptoms. Recognition only by isolation.
•Abortive Polio Or Minor Illness: occurs approximately in
4-8 per cent of the infection. It causes only a mild or self
limiting illness due to viraemia. The patient recovers
quickly.
•Non paralytic polio: occurs approximately in one per cent
of all infections. The presenting features are stiffness and
pain in neck and back. The disease lasts for two to ten
days. Recovery is rapid.
•Paralytic polio: occurs in less then one per cent of
infections. The virus enters the brain and causes varying
degree of disability.
  "Poliomyelitis" comes from the Greek word for gray,
  polio, and myelo, meaning spinal cord. The Latin suffix
  itis refers to inflammatory diseases.




Among children who are paralyzed by polio:
30% make a full recovery
•30% are left with mild paralysis
•30% have medium to severe paralysis
•10% die
Global Status 1988
GLOBAL STATUS 2004
   GLOBAL POLIO VIRUS CASES


1988             3,50 000
April 1, 2003,   1,925 polio cases
1998             1,934
1999             1,186
2000               265
2001               211
2002              1919
2003               784
2004             1,556
20.12.2005 -      1831
2005
1,831 cases of wild poliovirus (excludes vaccine derived polio viruses
[8]).
727 Nigeria (endemic) 478 Yemen (importation) 299 Indonesia
(importation) 154 Somalia (importation) 64 India (endemic) 27 Pakistan
(endemic) 27 Sudan (re-established transmission) 20 Ethiopia
(importation) 9 Angola (importation) 9 Niger (endemic) 7 Afghanistan
(endemic) 4 Nepal (importation) 3 Mali (importation) 1 Chad (re-
established transmission) 1 Eritrea (importation) 1 Cameroun
(importation)
Source: Polio cases from 1 January 2005, as of 17 January 2006
•25 million children are born in India every year.
•There is interval of 11 months between two PPIs.
•Over emphasis and too-frequent IPPI rounds and other
supplemental immunization activities left a grass root
health worker completely exhausted and fatigued.
•High population densities, poor sanitation, and low
routine immunization coverage.
•Resistance for OPV immunization amongst Muslim
community. OPV is an anti-fertility vaccine and would lead
to impotence in male children or infect them with AIDS.
• Children in western UP from Muslim community have
consistently been missed both during SIAs and for routine
immunization.
•Significantly almost 66% of polio cases have occurred
among Muslim children.
•A dwindling public involvement, and lack of commitment
of all sectors of local administration have hampered the
progress of this mass-campaign in the most populous and
political sensitive states of north India.
In 1993, Kerala became the first state in
India to conduct statewide immunization
day.
In 1994 Tamil Nadu became the second
state to conduct statewide immunization
day. Delhi became the third state,
conducting statewide immunization day
on 2nd October 1994 and 4th December
1994.First PPI held in 1995-96 all
children below 3 years of age were
targeted on 9th December 1995 and 20th
January 1996.
     POLIO ERADICATION PROGRAMME


•Conduct pulse polio immunisation for two days
every year for three to four years or until polio is
eradicated.
•Sustain high level of routine immunisation.
•Monitor OPV coverage at district levels and below.
•Improve surveillence capable of detecting all
cases of polio.
•Ensure rapid case investigation, including the
collection of stool samples.
•Arrange follow-up of all cases of paralytic polio at
60 days to check for residual paralysis.
•Conduct outbreak control for cases confirmed or
suspected to stop transmission.
            National Immunization Days
•   9.12.1995 - I st NID
•   20.01.1996
•   07.12.1996 – 2nd NID
•   18.01.1997
•   07.12.1997 – 3rd NID
•   18.01.1998
•   06.12.1998 – 4th NID
•   17.01.1999
•   24.10.1999 – 5th NID
•   21.11.1999
•   19.12.1999
•   23.01.2000
•   2004 - ( 5- NID, 3SID)
•   2005 – ( 2-NID, 6 SID)
               GOAL
    To assist governments in their efforts to
immunize every child against polio until polio
transmission has stopped, so that the world
can be certified polio-free.
From 1996-97 to all children under the age of 5
years were covered.
Till 1998-99, the PPI Programme consisted of
vaccination of children at fixed booths on two
National Immunization Days(NID), separated by six
weeks, during the winter season.
The strategy for 2000–2001 has been firmed up after
studying the epidemiological pattern of the disease in
different parts of the country and in consultation with
group of national / international experts, specially
constituted by WHO at the country’s request. their
advice is to adopt a differential approach in response
to the varying levels of success already achieved in
the different States.
The country has accordingly been divided into three zones : Low
Burden Zone (LBZ), Middle Burden Zone (MBZ) and High Burden
Zone (HBZ).
   Experts have suggested that there should be two
national immunization days in the months of December
2000 and January 2001, preceded by one Sub-National
Immunization Day for 11 States in the month of November
2000 and another SNID for the 4 States of UP, Bihar, West
Bengal and Delhi in the month of September 2000, which
are in the HBZ zone.
  The experts also advised that the house to house
component need not be insisted on the LBZ areas, while the
MBZ and HBZ should continue with the house to house
search and immunization programme, as some children in
these States are missing vaccination in the NIDs.
  As regards the LBZ and MBZ areas, experts have advised
mop up vaccination around each case of confirmed polio not
only in the district in which the case appears but also in the
surrounding districts.
  The Global Polio
Eradication Initiative
              OBJECTIVES:
• TO INTERRUPT TRANSMISSION OF THE WILD
  POLIOVIRUS AS SOON AS POSSIBLE AND CERTIFY
  ALL WHO REGIONS POLIO-FREE BY THE END OF
  2005;
• TO IMPLEMENT THE POLIO ENDGAME PROGRAMME
  OF WORK, INCLUDING CONTAINMENT OF WILD
  POLIOVIRUS,        GLOBAL        POLIO-FREE
  CERTIFICATION, AND THE DEVELOPMENT OF A
  POST-ERADICATION IMMUNIZATION POLICY;
• TO    CONTRIBUTE    TO    HEALTH   SYSTEMS
  DEVELOPMENT BY STRENGTHENING ROUTINE
  IMMUNIZATION     AND   SURVEILLANCE     FOR
  COMMUNICABLE DISEASES.
               Strategies:
• HIGH INFANT IMMUNIZATION COVERAGE WITH
  FOUR DOSES OF ORAL POLIO VACCINE IN THE
  FIRST YEAR OF LIFE;
• SUPPLEMENTARY DOSES OF ORAL POLIO VACCINE
  TO ALL CHILDREN UNDER FIVE YEARS OF AGE
  DURING NATIONAL IMMUNIZATION DAYS (NIDS);
• SURVEILLANCE FOR WILD POLIOVIRUS THROUGH
  REPORTING AND LABORATORY TESTING OF ALL
  CASES OF ACUTE FLACCID PARALYSIS (AFP)
  AMONG CHILDREN UNDER FIFTEEN YEARS OF
  AGE;
• TARGETED “MOP-UP” CAMPAIGNS ONCE WILD
  POLIOVIRUS TRANSMISSION IS LIMITED TO A
  SPECIFIC FOCAL AREA.
Before a WHO region can be certified polio-free,
three conditions must be satisfied:
( A) AT LEAST THREE YEARS OF ZERO POLIO
CASES DUE TO WILD POLIOVIRUS
( B) EXCELLENT CERTIFICATION STANDARD
SURVEILLANCE
( C) EACH COUNTRY MUST ILLUSTRATE THE
CAPACITY TO DETECT, REPORT AND RESPOND TO
“IMPORTED” POLIO CASES. LABORATORY STOCKS
MUST BE CONTAINED AND SAFE MANAGEMENT OF
THE WILD VIRUS IN INACTIVATED POLIO VACCINE
(IPV) MANUFACTURING SITES MUST BE ASSURED
BEFORE THE WORLD CAN BE CERTIFIED POLIO-
FREE.
In THERE   ARE FOUR GLOBAL PRIORITIES TO STOP TRANSMISSION
OF THE WILD POLIOVIRUS AND OPTIMIZE THE BENEFITS OF POLIO
ERADICATION :
1.     1. Substantial external financial resources are required to support the
efforts of developing countries to eradicate polio. These financial resources
must be secured to purchase oral polio vaccine (OPV), to plan and
implement national immunization days and mop-up campaigns, and to
cover surveillance and laboratory costs.
2.     2. India is the highest priority country, because it has the highest
number of cases in the world (83%), and for the first time in the
Initiative’s history, previously polio-free areas were reinfected, as the
epidemic in the north Indian state of Uttar Pradesh spread into such Indian
states as Gujarat, Rajasthan and West Bengal.
3.     3. As the world is nearing polio-free status, effective surveillance
becomes even more important to quickly identify any potential outbreaks
and manage them effectively. Achieving certification standard surveillance
is also a requirement for certifying the world polio-free.
4.     4. In conjunction with effective surveillance, it is essential that the
capacity is in place to rapidly mount massive immunization response
campaigns to manage any wild poliovirus importations quickly and
efficiently in polio-free areas
FUTURE BENEFITS OF POLIO ERADICATION
ONCE POLIO IS ERADICATED, THE WORLD CAN
CELEBRATE NOT ONLY THE ERADICATION OF A
DISEASE BUT THE DELIVERY OF A GLOBAL PUBLIC
GOOD – SOMETHING FROM WHICH EVERY PERSON,
REGARDLESS OF RACE, SEX, ETHNICITY, ECONOMIC
STATUS OR RELIGIOUS BELIEF, CAN BENEFIT FOR ALL
TIME, NO MATTER WHERE THEY LIVE.
THE HUMANITARIAN BENEFIT IS TREMENDOUS, AS
BETWEEN 2002 AND 2040, OVER TEN MILLION NEW
CASES OF POLIO WORLDWIDE WOULD MANIFEST
THEMSELVES. ADDITIONALLY, THE SAVINGS OF
POLIO ERADICATION ARE POTENTIALLY AS HIGH AS
US$ 1.5 BILLION PER YEAR – FUNDS THAT COULD BE
USED TO ADDRESS OTHER PUBLIC HEALTH
PRIORITIES.
VACCINE VIAL MONITOR
THE MAGNESIUM CHLORIDE STABILISED VACCINE WILL MAINTAIN
ADEQUATE IMMUNOGENICITY FOR 18 MONTHS WHEN KEPT IN A
REFRIGERATOR AT +2°C TO +8°C, FOR SIX WEEKS AT +25°C AND FOR
THREE DAYS AT +37°C.
AT -20°C, ALL FORMULATIONS AND PRESENTATIONS ARE VERY STABLE
AND NO LOSS OF POTENCY HAS BEEN OBSERVED OVER A PERIOD OF
MORE THAN FIVE YEARS.
VACCINES SHOULD BE INSPECTED VISUALLY FOR ANY PARTICULATE
MATTER AND/OR OTHER COLORATION PRIOR TO ADMINISTRATION.
DUE TO MINOR VARIATION OF ITS PH, POLIO SABIN™ (ORAL) MAY VARY IN
COLOUR FROM LIGHT YELLOW TO LIGHT RED. CHANGES OF THE
COLOUR OF THE VACCINE WITHIN THESE RANGES DO NOT SIGNIFY
DETERIORATION OF THE VACCINE.
THE VACCINE SHOULD BE STORED IN A REFRIGERATOR BETWEEN +2°C
AND +8°C OR IN A FREEZER AT -20°C. FREEZING AND THAWING DOES NOT
AFFECT THE TITRE OF THE VACCINE.
IN ORDER TO PRESERVE OPTIMAL POTENCY OF POLIO SABIN™ (ORAL),
EXPOSURE OF THE VACCINE TO AMBIENT (NON-REFRIGERATED)
TEMPERATURES SHOULD BE KEPT TO A MINIMUM AND EXPOSURE TO
SUNLIGHT SHOULD BE AVOIDED.
The IEAG also made the following recommendations regarding supplementary
immunisation schedule and vaccine:
• Use of mOPV1 in Bihar, UP and neighboring districts of Uttaranchal, Delhi, and
Mumbai/ Thane/Raigad during the May 2005 NID.
• Given the high probability of ongoing low level type 1 poliovirus transmission, and
the risk of further spread of this virus with the onset of the rainy season in June,
mOPV1 be used in a further round in the full supplementary NID (SNID) area (Bihar,
UP and neighboring districts of Uttaranchal, Delhi, and Mumbai/Thane/Raigad). Any
areas not covered with mOPV1 in the June SNID should use mOPV1 in the August
SNID.
• Trivalent OPV should be used for the SNIDs during the three remaining SNID
rounds in 2005 (August, October and November), except in areas where wild
poliovirus type 1 persists, in which case mOPV1 should be used in appropriate
districts for two sequential rounds.
• The geographic extent of the four SNIDs should be expanded to include any
additional areas or state where a wild poliovirus is isolated. If wild poliovirus type 1 is
isolated, mOPV1 should be used for at least two rounds in these areas.
• Trivalent OPV should be used for SIAs in 2006-2007 unless wild poliovirus is
isolated, in which case mOPV should be used in at least two sequential rounds in an
appropriate area.
Accurate surveillance for polio is essential for eradication.Surveillance systems
for polio have been developed under the guidance of the global polio eradication
initiative and use a combination of (1) identification of all potential cases of acute
flaccid paralysis (AFP), the most obvious manifestation of polio infection and (2)
laboratory evaluation of stools from these cases to confirm poliovirus as the
cause.
Surveillance of cases of acute flaccid paralysis among children less than 15 years
of age is a key component for a well functioning polio surveillance system. The
surveillance system works through a network of surveillance medical officers, the
responsibility of them lies in assisting the health services departments of all states
and maintaining a network of acute flaccid paralysis reporting sites and rapidly
investigating the cases.
AFP is defined as sudden onset of weakness and floppiness in any part of the
body in a child less than 15 years of age. In addition, paralysis in a person of any
age in whom polio is suspected is also reported. AFP surveillance is used to detect
cases of suspected polio to initiate investigation and control measures. Any case
meeting the case definition should be investigated and stool specimens collected.
              Case Definition:
In the Global Polio Eradication Initiative (PEI), acute
flaccid paralysis is defined as:
Any case of AFP in a child aged <15 years, or any case of
paralytic illness in a person of any age when polio is
suspected.
Acute: rapid progression of paralysis from onset to
maximum paralysis
Flaccid: loss of muscle tone, “floppy” – as opposed to
spastic or rigid
Paralysis: weakness, loss of voluntary movement
Any case meeting this definition undergoes a thorough
investigation to determine if the paralysis is caused by
polio.
           Components of AFP Surveillance
The objective of AFP surveillance is to detect the exact
geographic locations where wild polioviruses are
circulating in the human population. All cases of acute
flaccid paralysis in children aged <15 years are
rigorously investigated by a trained medical officer,
with collection of stool specimens to determine if
poliovirus is the cause of the paralysis. Analysis of the
location of polioviruses isolated from AFP cases allows
programme managers to plan immunization campaigns
(Pulse Polio Immunization) to prevent continuing
circulation of virus in these areas.
COMPONENTS OF AFP SURVEILANCE

1.The AFP surveillance network and case
notification
2.Case and laboratory investigation
3.Outbreak response and active case search in the
community
4.60-day follow-up, cross-notification
   and tracking of cases
5.Data management and case classification
6.Virologic case classification scheme
7. Surveillance performance indicators
The most important aspect of this classification is
the collection of 2 adequate stool samples from all
cases. Samples are considered adequate if both the
   specimens (1) are collected within 14 days of
paralysis onset and at least 24 hours apart; (2) are
  of adequate volume (8-10g) and (3) arrives at a
WHO-accredited laboratory in good condition (ie,
     no desiccation, no leakage), with adequate
     documentation and evidence of cold-chain
                    maintenance.
THE GLOBAL POLIO LABORATORY NETWORK IS A 3-TIER
PYRAMIDAL NETWORK OF
A TOTAL OF 145 LABORATORIES CLASSIFIED AS NATIONAL,
REGIONAL REFERENCE AND GLOBAL SPECIALISED
LABORATORIES.
THE INDIAN NETWORK IS COMPRISED OF A TOTAL OF EIGHT
LABORATORIES WITH ONE GSL AND SEVEN NPL.
THESE ARE STRATEGICALLY LOCATED IN DIFFERENT PARTS OF
THE COUNTRY FOR QUICK, EASY ACCESS BY THE
SURVEILLANCE SYSTEM.
A SPECIFIC GEOGRAPHICAL AREA IS SERVED BY EACH
LABORATORY. ALL LABORATORIES IN THE GLOBAL POLIO
NETWORK FOLLOW STRICT BIO-SAFETY LEVEL 2 FACILITIES.
AND ALSO USE (A) IDENTICAL TESTING PROCEDURES AND HIGH
QUALITY EQUIPMENT AND REAGENTS, (B) HAVE INSTITUTED
QUALITY ASSURANCE PROGRAMMES AND (C) UNDERGO
ANNUAL PROFICIENCY TESTING AND ON-SITE EVALUATION BY
WHO FOR ACCREDITATION.
Reference:
www.who.int
www.mohfw.nic.in
www.polioeradication.org
 www.unicef.org/immunization
Super course/ Pittsburgh
university(www.pitt.edu/~super1)
JIMA DECEMBER 2005
http://www.polionet.org/vaccine.htm
www.npspindia.org

								
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