• Control - Reduction of disease incidence, prevalence, morbidity, or mortality to a locally acceptable level as a result of deliberate efforts. The disease still exists but is no longer a significant public health problem. (Example: Diarrheal diseases, malaria in many regions)
• Elimination - Reduction of case incidence to zero in a defined geographical area. The disease no longer occurs locally but the causative agent may still exist elsewhere, so intervention measures must continue. (Example: Polio eliminated from India)
• Eradication - Permanent reduction to zero of the worldwide incidence of infection caused by a specific agent. Intervention measures are no longer needed. (Example: Smallpox - declared eradicated in 1980)
• Extinction - The specific infectious agent no longer exists in nature or in the laboratory. (True extinction has not been achieved for any human pathogen)

Reference: Park's Textbook of Preventive and Social Medicine defines "control" as reducing disease/disability to the point that it is no longer a major public health problem, while "elimination" and "eradication" imply progressively complete removal of the agent.