Disease Eradication Prof. Ashry Gad Mohamed Consultant Epidemiologist

Terms Control: Reduction of incidence, prevalence, morbidity and mortality to locally accepted level. E.g. DD 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 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 E.g. Measles & poliomyelitis Deliberate efforts Continuous efforts

Eradication Permanent reduction of the worldwide incidence of infection to zero. e.g. smallpox e.g. smallpox Deliberate efforts No Continuous efforts

Extinction The specific infectious agent no longer exists in the nature or laboratory. None 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 Forest yellow fever Idea of eradication is discredited. is discredited.

1939: 1960 Eradication of Anopheles gambiae and Aedes aegypti in South America 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 long- - Eradication programs are usually long- term often requiring international term often requiring international cooperation. cooperation. - Political upheaval and war usually disrupt - Political upheaval and war usually disrupt eradication projects. eradication projects.

Popular support -Costs & inconvenience. -Costs & inconvenience. -It should have particular public health -It should have particular public health importance locally. importance locally. - Funds - FundsTechnology Equipment Equipment Transport Transport Administrative organization Administrative organization

Biological factors I-Related animal infections Identical (zoonoses): A: If wild animals are involved then eradication is difficult if not impossible. A: If wild animals are involved then eradication is difficult if not impossible. e.g. rabies, yellow fever & salmonella. e.g. rabies, yellow fever & salmonella. B: If only domestic animals are involved then regional eradication is possible e.g. bonine TB & brucella. 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 yellow fever virus & arbor viruses in India. in India.

Economic consideration Health resources allocation. Effects Direct No morbidity Direct No morbidity No mortality No mortality Control programs can cease Control programs can ceaseConsequences Positive Vs Negative 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 2000 Measles 2010 Trachoma 2020 VAD 2020 IDD 2020 Chagas disease 2010 Leprosy 2010