Epidemiology

1. Disease Eradication

2. Definition
Eradication
It is an absolute process an “ all or none”
phenomenon.
Restricted to termination of an infection
from the whole world.

3. Definition
It is sometimes confused with:
1. Elimination:
Which used to describe of eradication 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.

4. Eradication Criteria
1. The targeted organism must not have a non-human
reservoir.
 This implies that sufficient information on the life
cycle and transmission dynamics is available at the
time an eradication initiative is programmed.
 In the 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.

5. 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.

6. Eradication Criteria
4. Economic considerations, as well as social
and political support and commitment, are
other crucial factors that determine
eradication feasibility.

7. Eradication Programs
Two successful programs targeting
1. Smallpox
2. Rinderpest

8. Eradication Programs
Two former programs targeting
1. Hookworm
2. Yellow fever

9. Eradication Programs
Four ongoing programs targeting
1. Poliomyelitis
2. Yaws
3. Dracunculiasis
4. Malaria

10. 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

11. Successful Eradication Programs

12. Smallpox
 Smallpox was the first disease, and so far the only infectious
disease of humans, to be 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

13. Smallpox
Eradication was accomplished with a
combination of focused surveillance—quickly
identifying new smallpox cases—and ring
vaccination.

14. 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.

15. Smallpox
Last natural smallpox case was of Ali Maow
Maalin in, Merca/ Somalia on October 26:1977

16. Rinderpest
• 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

17. • The final, successful campaign was led by the Food
and Agriculture Organization (FAO) of the United
Nations.

18. Rinderpest
 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.

19. Ongoing Eradication Programs

20. 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. Measle
s
 The measles vaccine is effective at preventing the
disease?
 Vaccination has resulted in a 75% decrease in deaths
from measles between 2000 and 2013 with about
85% of children globally being currently vaccinated.

23. Measle
s
 In 2009 the regional committee for Africa agreed a
goal of measles elimination by 2020
 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

24. Measle
s
 The Americas set a goal in 1994 to eliminate measles
transmission by 2000, and successfully achieved
regional measles elimination in 2002.
 As of February 2015, measles is no longer
eliminated in the US.
 From January 1 to April 10, 2015, 159 people were
reported to have measles.
 most of these cases [117 cases (74%)] are part of a large,
multi-state outbreak linked to an amusement park in California

25. Measle
s
 At the 63rd World Health Assembly in May 2010,
delegates agreed to move towards eradication,
although no specific global target date has yet been
agreed

26. History of polio…
• The disease of poliomyelitis has a
long history.
• The first example may even have been
more than 3000 years ago.
• An Egyptian stele dating from the
18th Egyptian dynasty shows a priest
with a deformity of his leg
characteristic of the flaccid paralysis
typical of poliomyelitis.
3-Poliomyelitis (polio)

27. Poliomyelitis(pol
io)
• The 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%.
• In 2013, only three countries in the world remain polio-
endemic: Nigeria, Pakistan andAfghanistan

28. Poliomyelitis(pol
io)
Middle East:
The most recent case reported from Syria had
onset of paralysis on 21 January 2014, while in
Baghdad-Resafa province, on 7 April 2014.
Horn ofAfrica
The most recent case, which had onset of
paralysis on 11 August 2014, was from central
Somalia

29. 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

30. The Global Polio Eradication Initiative
Four Pillars of the Global Polio Eradication
Initiative Strategy:
1. Routine Immunization.
2. Supplemental ImmunizationActivities.
3. Acute Flaccid Paralysis (AFP) Surveillance.
4. Targeted Mop-Up Campaigns.

31. 1. Routine Immunization
• A major cornerstone of the polio eradication strategy
• According to WHO/UNICEF immunization
coverage estimates, 86% of infants received three
doses of oral polio vaccine in 2010, compared with
75% in 1990.
The Global Polio Eradication Initiative

32. 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.
The Global Polio Eradication Initiative

33. The Global Polio Eradication Initiative
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.

34. The Global Polio Eradication Initiative
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.

35. The Global Polio Eradication Initiative
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
exacerbate communities’ vulnerability topolio.

36. Conclusi
on
• 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.
• But the outbreak also serves as a reminder that high vaccination
coverage is essential in countries where the disease is not currently
circulating.

37. Former Eradication Programs
Hookworm
Hookworm infection is caused by the
transmission of the hookworm parasite common
to warmer climates.
Hookworm larvae live in soil and typically enter
humans through the soles of their feet
Hookworm eradication campaign start at US in
1909

38. 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.
 In North American countries, such as the United
States, elimination of hookworm had been attained .