Transcript Disease Eradication

Disease Eradication
Prof. Ashry Gad Mohamed
Consultant Epidemiologist
Terms
Control: Reduction of incidence,
prevalence, morbidity and mortality to
locally accepted level.
E.g. DD
Deliberate efforts
Continuous efforts
Elimination of Disease
Reduction of disease incidence to zero in
a defined geographical area.
E.g. Neonatal tetanus
Deliberate efforts
Continuous efforts
Elimination of Infection
Reduction of infection incidence to zero in
a defined geographical area.
E.g. Measles & poliomyelitis
Deliberate efforts
Continuous efforts
Eradication
Permanent reduction of the worldwide
incidence of infection to zero.
e.g. smallpox
Deliberate efforts
No Continuous efforts
Extinction
The specific infectious agent no longer
exists in the nature or laboratory.
None
No Deliberate efforts
No Continuous efforts
WHO malaria eradication definition
“The ending of the transmission of
malaria and the elimination of the
reservoir of infective cases in a
campaign limited in time and carried
to such a degree of perfection that
limited in time and carried to such a
degree of perfection that when it
comes to an end, there is no
resumption of transmission”
History
1892: Contagious pleuro-pneumonia
of cattle in USA.
1896: Rabies through enforcing a
muzzling order for all dogs for one
year & enforcing a three months
quarantine for all dogs and cats at
their owner’s house.
1917: Bovine tuberculosis
Testing of all cattle in the United States and
the killing of the reactors.
Extremely costly
Failure
1910: Yellow fever was eradicated from
Cuba by anti-mosquito measures.
Forest yellow fever
Idea of eradication
is discredited.
1939: 1960 Eradication of Anopheles
gambiae and Aedes aegypti in South
America.
1980
Eradication of smallpox.
Indicators of eradicability
Effective intervention.
Practical diagnostic tools.
Human are essential for the life
cycle of the agent.
Basic Program Needs
Political stability
- Eradication programs are usually longterm often requiring international
cooperation.
- Political upheaval and war usually disrupt
eradication projects.
Popular support
-Costs & inconvenience.
-It should have particular public health
importance locally.
- Funds
Technology
Equipment
Transport
Administrative organization
Biological factors
I-Related animal infections
Identical (zoonoses):
A: If wild animals are involved then
eradication is difficult if not impossible.
e.g. rabies, yellow fever & salmonella.
B: If only domestic animals are involved
then regional eradication is possible e.g.
bonine TB & brucella.
Closely related
Species sharing the same ecologies
compete with one another.
yellow fever virus & arbor viruses
in India.
Economic consideration
Health resources allocation.
Effects
Direct
No morbidity
No mortality
Control programs can cease
Consequences
Positive Vs Negative
Social & Political criteria
High level of societal & political
commitment to the program from the
beginning to end.
Recognized public health importance &
international appeal.
Field tested intervention.
Simple, clear & outcome oriented
program.
Diseases for eradication
Poliomyelitis
Measles
Trachoma
VAD
IDD
Chagas disease
Leprosy
2000
2010
2020
2020
2020
2010
2010