Home' Rotary Down Under : February 2014 (NZ Pacific) Contents www.rotarydownunder.org 33
The four objectives of the GPEI endgame strategy
(1) Stop transmission India was long regarded as the most
difficult place to end polio, but through innovation and hard
work, the country has gone three years without a case. The endgame
strategy builds on this success with a plan to interrupt all wild poliovirus
transmission by the end of 2014. It will require rapid detection of the
poliovirus, reaching all children in the three polio-endemic countries,
preventing outbreaks in areas prone to re-importation by maintaining
immunity levels above a set threshold, rapidly responding to any new
outbreaks, and enhancing the safety of immunizers.
polio vaccine with the inactivated version The new plan
lays out a strategy to use the existing GPEI best practices and
infrastructure to build a stronger system for the delivery of polio vaccine
and other lifesaving vaccines, working closely with the GAVI Alliance,
a global partnership of public- and private-sector organizations
dedicated to immunizations for all.
The oral polio vaccine has been the vaccine of choice for the polio
eradication effort because it’s affordable, easy to administer, and
induces “passive immunity” in the community. That is, because the
vaccine is made from a live but weakened version of the virus, the
vaccine-virus replicates in the intestines, is excreted, and then spreads
through areas with poor sanitation, inducing immunity in others before
it dies out. In very rare cases, the excreted vaccine-virus can mutate
back to a more virulent, transmissible version and cause paralysis and
outbreaks. As the end of polio draws near, the GPEI plans to introduce
at least one dose of the inactivated polio vaccine into routine
immunization systems. It is more difficult to administer but is made of
a killed version of the virus, which cannot mutate and cause infection.
(3)Contain and certify For a region to be certified polio-free,
it must go three years without any reported cases. To be sure
there are truly no cases of polio, the region relies on a highly sensitive
surveillance system to seek out and test cases of paralysis for the
poliovirus. The area also needs a way to safely handle the poliovirus
for vaccine production, research, and diagnostic facilities, to ensure
that the virus doesn’t escape and cause an outbreak. So far, the Western
Pacific, European, and Americas regions of the World Health
Organization have been certified polio-free, and the South-East Asia
region could be certified by the end of the year, leaving only the African
and Eastern Mediterranean regions to be certified.
(4)Plan polio’s legacy Over the past 25 years, the GPEI has
trained millions of volunteers, influencers, and health workers.
It has reached the most marginalized and vulnerable populations in the
world and developed an unprecedented global surveillance and response
network, which is already helping to combat other vaccine-preventable
diseases and providing assistance during humanitarian disasters. By
sharing this blueprint, not only will polio be eradicated but a legacy will
be created that will support other health and development initiatives.
eradication initiative; without it, pinpointing where
and how wild poliovirus is still circulating is
impossible. Acute flaccid paralysis – sudden floppiness or
lifelessness in an arm or leg – is the most characteristic
symptom of poliovirus infection among infants and
children, and monitoring regions for the condition
is the standard for poliovirus detection. Health
officials follow these four surveillance steps
to identify new cases and detect importation
of the wild poliovirus:
Report child with
A health worker reports a child with acute flaccid
paralysis People who work in health facilities
are the first links in the surveillance chain.
They are responsible for reporting every case of
floppy, lifeless limbs they encounter in children
younger than 15. Public health employees also
periodically visit at-risk communities to look for new
cases of suspected polio. In areas with few health
workers, some regions rely on local pharmacists,
traditional healers, or religious leaders to serve as
community watchdogs and a source of information
on paralyzed children. In these areas, posters alerting
villagers to what acute flaccid paralysis looks like and how
to report potential cases hang throughout many towns.
Workers take stool samples and transport them for analysis
When polio is suspected, a doctor conducts a complete
physical exam to determine whether the patient has lifeless
limbs and other signs consistent with paralytic polio.
Several disorders can cause acute flaccid paralysis, so all
children with lifeless limbs must have their stool tested for
polio within 48 hours of the onset of paralysis. The samples
must be taken 24 to 48 hours apart to account for any
variability in the excretion of the virus.
THE ROTARIAN | FEBRUARY 2014
feb14-61-68-Global Outlook-EndGame-v11.indd 66
12/11/13 10:20 AM
FEBRUARY 2014 | THE ROTARIAN
Continue regular immunization campaign.
Scientists isolate the poliovirus Scientists
treat special cells with extracts from the stool
samples and place them in an incubator. The
cultured cells are examined over a period of
two weeks for the growth of the poliovirus.
Once the presence of poliovirus is confirmed,
virologists distinguish between the wild
(naturally occurring) and vaccine-related
poliovirus. The latter refers to rare strains of
the virus that have genetically mutated from
the original strain contained in the oral polio
vaccine. If wild poliovirus is isolated, the
virologists identify which of the two surviving
types is involved. Only types 1 and 3 continue
to circulate in polio-endemic areas.
Experts map the virus and create an immunization strategy Once virologists have identified wild poliovirus in a stool sample, scientists perform
additional tests to determine where the strain originated. They sequence a specific portion of the virus’ genome and compare the resulting pattern to
reference samples of already sequenced polioviruses circulating in different geographic areas. Once they find a match and pinpoint the new virus to a
precise location, scientists can identify the source of importation – both long-range across regions and local cross-border – and determine the
appropriate immunization strategy to prevent further spread.
feb14-61-68-Global Outlook-EndGame-v11.indd 67
12/11/13 10:20 AM
Links Archive Dec 2013-Jan 2014 March 2014 (NZ Pacific) Navigation Previous Page Next Page