Dynamics of Disease Transmission Flashcards
What is the Epidemiologic Triad of Disease?
a model used to understand the interaction between three key elements in the spread and development of disease
Epidemiologic Triad of Disease includes
- Agent
- Host
- Environment
- Vector
Host factors include
- Demographics: (Age, sex, ethnic group)
- Behaviors (Smoking, drinking, exercise)
- Physiologic state (Pregnancy, puberty, fatigue)
- Vaccinations
What is an agent
A microorganism, chemical, nutritive element, or physical factor whose presence or absence is essential for a particular disease or condition to occur
Types of Agents include
Bacteria
Radiation
Virus
Chemicals
Protozoa
Parasite
Fungi
Heat/cold
Diet deficiency
Genetic traits
Diet excess
Stress
Environmental Factors include
- Physical (Weather, climate, geology)
- Biological (Sources of food, water, and air)
- Social and cultural (Density, crowding, adequate housing)
Example of epidemiologic triad for Malaria
Identify the following:
Host?
Agent?
Environment?
Vector?
Host: Human
Agent: Plasmodium Vivax
Environment: Humidity control measures
Vector: Mosquito
Example of epidemiologic triad for Violence
Identify the following:
Host?
Agent?
Environment?
Vector?
- Host: Human
2: Agent: Weapons
3: Environment: Poverty & Substance Abuse
4: Vector: Other humans
Iceberg concept of Infectious disease, s severity increases
frequency decreases
primary prevention includes
Exposure
&
Stages of Susceptibility
Secondary prevention includes
Pathologic changes
&
Stage of subclinical disease
Tertiary prevention includes
Stages of clinical disease
Stages of recovery, disability or death
Usual time of diagnosis
Stage 1 of Natural history of disease
Susceptibility
Description and example of Susceptibility
Risk factors that assist the development of
disease exist, but the disease has not developed
ex. Smoking
Stage 2 of Natural history of disease
Presymptomatic disease
Description and example of presymptomatic disease
Changes have occurred to lead toward illness
but disease is not yet clinically detectable
Ex. Alveoli deteriorate
Stage 3 of natural history of disease
Clinical disease
Description and example of clinical disease
Detectable signs and/or symptoms of
disease exists
ex. Emphysema detected by pulmonary function test
Stage 4 of natural history of disease
Disability
Description and example of disability
Disease has progressed to the point of
causing a residual effect
ex. Person has difficulty breathing
