Past and future of eradication and elimination of different diseases. How to plan for elimination and eradication. What are the diseases can be eliminated? OPV to IPV shift!
3.
Definition
Eradication
Termination of all transmission of infection by
extermination of the infectious agent through surveillance
and containment.
Absolute process; an “all or none” phenomenon.
Restricted to termination of an infection from the whole
world.
4.
Definition
It is sometimes confused with:
Elimination: interruption of transmission of disease
from a large geographic region or political jurisdiction.
When a disease stops circulating in a region, it’s
considered eliminated in that region.
If a particular disease is eliminated worldwide, it’s
considered eradicated.
For example, Polio was eliminated in the United States by
1979.
5.
Eradication Criteria
Both biological and technical features determine whether a
pathogenic organism can be eradicated or not.
1. The targeted organism must not have a non-human reservoir.
Sufficient information on the life cycle and transmission
dynamics is available at the time an eradication initiative is
programmed.
In case of animal diseases, the infection reservoir must be
an easily identifiable species (as in the case of rinderpest),
and/or amplify in the environment.
6.
Eradication Criteria
2. An efficient and practical intervention (e.g., vaccine)
must be available to interrupt transmission of the
infective agent.
3. The disease to be eradicated should be clearly
identifiable, and an accurate diagnostic tool should exist.
4. Economic considerations, as well as social and political
support and commitment, are other crucial factors that
determine eradication feasibility.
8.
Eradication Programs
Two former programs
targeting
1. Hookworm
2. Yellow fever
Four ongoing programs
targeting
Poliomyelitis
Yaws
Dracunculiasis
Malaria
9.
Eradication Programs
Five more infectious diseases have been identified
as of April 2008 as potentially eradicable with
current technology:
1. Measles
2. Mumps
3. Rubella
4. Lymphatic filariasis
5. Cysticercosis
10.
11.
Smallpox
Smallpox was the first disease, and so far the only infectious
disease of humans, eradicated by deliberate intervention.
It became the first disease for which there was an effective
vaccine in 1798 when Edward Jenner showed the protective
effect of inoculation (vaccination) of humans with material
from cowpox lesions
Eradication was accomplished with a combination of focused
surveillance—quickly identifying new smallpox cases—and
ring vaccination.
12.
Smallpox
“Ring vaccination” meant that
anyone who could have been
exposed to a smallpox patient
was tracked down and vaccinated
as quickly as possible, effectively
corralling the disease and
preventing its further spread.
13.
Smallpox
Epidemiological factors which have led to eradication of
smallpox:
1. No known animal reservoir.
2. No long-term carrier of the virus.
3. Life-long immunity, after recovery from the disease.
4. Simple detection of cases , the rash was so characteristic and
occurred in visible parts of the body.
5. Persons with subclinical infection did not transmit the disease
6. Vaccine highly effective, easily administered, heat stable, and
confers long term protection.
7. International cooperation.
14.
It is a viral disease which infected cattle and other ruminants and
belonged to the same family as measles.
During the 20th century, there were a series of campaigns to
eradicate it, through the use of a live attenuated vaccine.
The final, successful campaign was led by the Food and
Agriculture Organization (FAO) of the United Nations.
On 14 October 2010, with no diagnoses for nine years, the FAO
announced that the disease had been completely eradicated.
It is the first (and so far the only) disease of livestock to have
been eradicated by human undertakings.
Rinderpest
15.
16.
Dracunculiasis
(Guinea worm disease)
It is a painful and disabling parasitic disease caused by a
worm, Dracunculus medinensi.
It is spread through consumption of drinking water infested
with copepods hosting the larvae.
Guinea worm disease is set to become the second human
disease in history, after smallpox, to be eradicated.
It will be the first parasitic disease to be eradicated and the
first disease to be eradicated without the use of a vaccine or
medicine.
17.
18.
Dracunculiasis
Eradication efforts have been based :
1. On making drinking water supplies safer (e.g. through
treating the water with larvicide).
2. Containment of infection.
3. Education for safe drinking water practices.
19.
Dracunculiasis
The original goal for eradication was 1995.
Two decades of eradication efforts have reduced guinea
worm's global incidence to: more than 99.99% to 126 cases
in 2014, down from an estimated 3.5 million in 1986.
South Sudan, the world's youngest nation, reported 70 cases or
56 percent of the worldwide case total in 2014.
20.
2016: Dracunculiasis of humans was reported in
three countries, namely:
Chad: 16 cases
Ethiopia: 3 cases
South Sudan: 6 cases
2017: Chad has so far confirmed 3 human cases
Dracunculiasis
21.
Measles
It is an airborne disease
Spreads easily through the coughs and sneezes of
those infected and contact with saliva or nasal
secretions.
Nine out of ten people who are not immune who
share living space with an infected person will
catch it.
22.
23.
Measles
Vaccination has resulted in a 75% decrease in deaths
from measles between 2000 and 2013 with about 85% of
children globally being currently vaccinated.
In 2009 the regional committee for Africa agreed a goal of
measles elimination by 2020.
24.
Measles
Europe had set a goal to eliminate measles transmission by
2010, but were hindered by:
• The MMR vaccine controversy ?
• They have set a new target of 2015
In 2016, an international expert committee determined that
America had eliminated endemic transmission of measles.
25.
Measles
The 11 member states of WHO South-East Asia Region
committed to eliminate measles by 2020 at the 66th Session of
the WHO Regional Committee for South-East Asia in sept
2013.
On 13 June, 2017, WHO declared that Bhutan and Maldives
have eliminated measles.
26. Challenges
Funding: specially for the follow-up
campaigns :
National managerial Capacity:
Inadequate number and qualification of
staff
Competing priorities:
Polio eradication
Pockets of susceptible
populations/groups
Hard to reach populations in low
income countries
Pockets in countries with big expatriate
population
Security situation: rapidly deteriorating
in the EMR
Delayed implementation of planned
activities
Financial support from
international partners
Interest of the countries
Polio infrastructures
Opportunities
Measles
27.
History of polio…
• The disease of poliomyelitis has a
long history.
• The first example may even have been
more than 3000 years ago.
Poliomyelitis (polio)
28.
World Health Assembly launched the Global Polio Eradication
Initiative (GPEI) in 1988.
Since the GPEI was launched, the number of cases has fallen by
over 99%.
Polio remains endemic in: Nigeria, Pakistan and Afghanistan.
Outbreak countries: Democratic republic of the Congo,
Syrian arab republic.
Poliomyelitis (polio)
29.
Poliomyelitis (polio)
Middle East:
June 2017: In Syria, a cVDPV2 outbreak has been
confirmed. The virus strain was isolated from two cases
of acute flaccid paralysis (AFP) and one healthy contact.
Pakistan – one new WPV1- positive environmental sample
in August 2017.
30.
Poliomyelitis (polio)
India
2009: India had half the number of polio cases in the
world, and in less than two years, polio infections were
brought down to zero.
The last case of polio in the country was reported from
Howrah, West Bengal on January 13, 2011.
India was declared non endemic for polio on 27th
march,2014.
33.
The Global Polio Eradication
Initiative(GPEI)
Objectives:
To interrupt transmission of wild poliovirus as soon as possible
To achieve certification of global polio eradication
To contribute to health systems development and strengthen
routine immunization and surveillance for communicable
diseases
4 Pillars of the Global Polio Eradication Initiative Strategy:
1. Routine Immunization.
2. Supplemental Immunization Activities.
3. Acute Flaccid Paralysis (AFP) Surveillance.
4. Targeted Mop-Up Campaigns.
34.
1. Routine Immunization
According to WHO/UNICEF immunization coverage estimates,
86% of infants received three doses of oral polio vaccine in 2010,
compared with 75% in 1990.
Good routine OPV coverage:
1. Increases population immunity
2. Reduces the incidence of polio
3. Makes eradication feasible plan of routine immunization for
out reach areas.
GPEI
35.
GPEI
2. Supplemental Immunization Activities
Mass polio immunization campaigns that complement routine
immunization programs are intended to:
Interrupt transmission by immunizing every child under the
age of 5 with oral polio vaccine annually, regardless of the
number of times they have been immunized previously.
36.
GPEI
3. Acute Flaccid Paralysis (AFP) Surveillance
As many as 90% of people infected with the poliovirus
experience very mild or no symptoms.
A single symptomatic case can therefore represent a
significant community-wide outbreak.
Robust surveillance to detect and investigate every case of
polio-like AFP is essential to polio eradication.
37.
GPEI
4. Targeted Mop-Up Campaigns
Last stage in polio eradication
Low routine immunization coverage: very dense or mobile
populations, inadequate sanitation, and poor access to health
services.
In focal areas where polio cases have been confirmed within
the previous 3 years and circulating virus is confirmed or
suspected.
In mop-up campaigns vaccinators go house-to-house to
immunize every child under 5 and help to stop transmission.
38.
OPV CESSATION
OPV is extremely safe and effective at protecting children
against lifelong polio paralysis. Over the past ten years, more
than 10 billion doses of OPV have been given to nearly three
billion children worldwide.
The disease has been reduced by more than 99%. It is the
appropriate vaccine through which to achieve global polio
eradication.
39. On extremely rare occasions, use of OPV can result in cases of
polio due to vaccine-associated paralytic polio (VAPP) and
circulating vaccine-derived polioviruses (cVDPVs).
For this, the global eradication of polio requires the cessation
of all OPV in routine immunization, as soon as possible after
the eradication of wild poliovirus (WPV) transmission.
OPV CESSATION
40.
OPV CESSATION:
The switch
The type 2 component of tOPV:
– Causes >90% of VDPV cases.
– Causes approx. 40% of VAPP cases(approx. 200 cases per year
worldwide).
– Interferes with the immune response to poliovirus types 1 and 3 in
tOPV.
In April 2016 a switch was implemented from trivalent OPV to
bivalent OPV in routine immunization programs.
Following WPV1 and WPV3 eradication, use of all OPV in routine
immunizations will be stopped. Only IPV will be used by 2020.
http://polioeradication.org/polio-today/preparing-for-a-polio-free-world/opv-cessation/
41.
May 2015
World Health Assembly consider a resolution on the
OPV switch
December
2015
At least 1 dose of IPV introduced into routine
immunization programmes in all countries
April 2016 Withdraw type 2 OPV globally
2020?
After all wild polioviruses have been fully eradicated,
withdraw all OPVs
OPV CESSATION
• Dates for the Endgame Plan:
42.
GPEI
Before a WHO region can be certified polio-free, the
following 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.
43.
The goal of the 2013-2018 Polio Eradication
and Endgame Strategic Plan is to complete the
eradication and containment of all wild, vaccine-
related and Sabin polioviruses, such that no
child ever again suffers paralytic poliomyelitis.
GPEI
44.
At present, polio is endemic in three countries
Until poliovirus transmission is interrupted in these strongholds, all
countries remain at risk, as shown not only by the outbreak in
Syria, but also in recurrent outbreaks across sub-Saharan
Africa, including an ongoing outbreak in Somalia.
Outbreak also serves as a reminder that high vaccination coverage is
essential in countries where the disease is not currently circulating.
Summary
45.
Former Eradication Programs
Hookworm
Hookworm infection is caused by the transmission of the
hookworm parasite common in warmer climates.
Hookworm larvae live in soil and typically enter humans
through the soles of their feet.
Hookworm eradication campaign was started at US in 1909.
The Rockefeller Sanitary Commission (RSC) was created with
the intention of eliminating the disease across the region. By
implementing a three-pronged approach, including mapping
the disease, curing patients, and providing education.
RSC dramatically reduced the disease burden.
http://rockefeller100.org/exhibits/show/health/eradicating-hookworm
46.
Hookworm
700 million people worldwide, including 44 million pregnant
women.
Tropical or sub-tropical environments in poverty-stricken
areas of Africa, Latin America, Southeast Asia and China.
2001: WHO adopted a resolution aimed at the deworming of
75% of all at-risk school-age children by 2010.
A hookworm vaccine is currently in Phase I clinical trial by
Sabin PDP.
The 2012 WHO Road Map added 75% coverage of all at-risk
pre-school-age children.
In United States, elimination of hookworm had been attained.
http://www.nejm.org/doi/full/10.1056/NEJMra032492#t=article
47.
48.
49.
Conclusion
It is useful to consider the successful eradication
programs, these programs could form the basis for
eradication for other diseases.
Both biological and technical features of the disease
should be considered before starting an eradication
programme.
We have to put in our knowledge of the economic , social
and political issues before setting a specific global target
date for any eradication programme.
