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Introduction to Epidemiological Methods. Bioterrorism Epidemiology Module 4 Missouri Department of Health And Senior Services. Learning Objectives. Define bioterrorism epidemiology Describe epidemiological approach to understanding disease etiology
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Introduction to Epidemiological Methods Bioterrorism Epidemiology Module 4 Missouri Department of Health And Senior Services
Learning Objectives • Define bioterrorism epidemiology • Describe epidemiological approach to understanding disease etiology • Recognize difference between incidence and prevalence • Distinguish between the stages of the disease process
Biological and Chemical Epidemiology The study of the distribution and determinants of diseases resulting from a biological or chemical attack
Sources of Epidemiologic Clues to a Disease Outbreak • Clinician’s office or medical clinic • Emergency room • Laboratory • Veterinary Clinic • Pharmacy
Epidemiologic Approach to Understanding Disease Etiology • Descriptive epidemiology - identifying associations of disease in relation to • Time • Place • Persons
Epidemiologic Approach to Understanding Disease Etiology • Analytic epidemiology • Identify associations of disease with possible etiologic factors (chemical release, biological agent) • Further refine and test hypotheses regarding etiology
Problems Investigating the Causes of Disease • Specific agent might not be known • Location of agent release might not be known • Signs and symptoms might not differentiate disease • More than one agent might be used • Time of agent release might not be known • Latency period might not be known • Latency is not the same for all people
Epidemiologic Triad of Disease Host Agent Environment
Epidemiologic Triad of Disease Host Agent Environment
Epidemiologic Triad of Disease Host Agent Environment
Epidemiologic Triad of Disease Host Agent Environment
Modes of Transmission Host • Direct • Contact • Droplets • Indirect • Airborne • Vehicle-borne • Vector-borne • Mechanical • Biologic Agent Environment
Modes of Transmission Host • Direct • Contact • Droplets • Indirect • Airborne • Vehicle-borne • Vector-borne Agent Environment
What Is a Numerator • Count of cases
What Is a Numerator • Count of cases • Frequently organized in a line-listing
What Is a Numerator • Count of cases • Frequently organized in a line-listing • Allows for regrouping and counting cases by their various characteristics
What Is a Numerator • Count of cases • Frequently organized in a line-listing • Allows for regrouping and counting cases by their various characteristics • Might be incident or prevalence cases
Incidence and Prevalence Incidence=
Incidence and Prevalence Number ofnew cases of a disease over a period of time Incidence=
Incidence and Prevalence Prevalence=
Incidence and Prevalence Total number of cases of a disease Prevalence=
Relationship Between Incidence and Prevalence Recovery Death Incidence Prevalence Pot
Relationship Between Incidence and Prevalence Recovery Death Incidence Prevalence Pot
Relationship Between Incidence and Prevalence Recovery Death Incidence Prevalence Pot
Relationship Between Incidence and Prevalence Recovery Death Incidence Prevalence Pot
Relationship Between Incidence and Prevalence Recovery Death Incidence Prevalence Pot
Relationship Between Incidence and Prevalence Recovery Death Incidence Prevalence Pot
Relationship Between Incidence and Prevalence Recovery Death Incidence Prevalence Pot
Relationship Between Incidence and Prevalence Recovery Death Incidence Prevalence Pot
Relationship Between Incidence and Prevalence Recovery Death Incidence Prevalence Pot
Relationship Between Incidence and Prevalence • Under the assumption of a steady-state Prevalence = I * D I = incidence D = duration Recovery Death Incidence Prevalence Pot
Relationship Between Incidence and Prevalence • Under the assumption of a steady-state Prevalence = I * D I = incidence D = duration Recovery Death Incidence Prevalence Pot
Relationship Between Incidence and Prevalence • Under the assumption of a steady-state Prevalence = I * D I = incidence D = duration Recovery Death Incidence Prevalence Pot
Episodes of Tularemia Number of Persons M L K J I H G F D E C B A TIME
Episodes of Tularemia Number of Persons M L K J I H G F D E C B A TIME
Episodes of Tularemia Number of Persons M L K J I H G F D E C B A TIME
Episodes of Tularemia Number of Persons M L K J I H G F D E C B A TIME