Utopia
Ch. 2: Fundamentals of Epidemiology
Causality: determining the cause of a disease
Screening test: test given to people who have no symptoms to check for the presence of a particular disease
Natural History of Disease: the course of disease if left untreated
Latency period: time from start of disease process until signs/symptoms appear
(Incubation period: time b/w infection & clinical disease)
Nonclinical stage: no signs/symptoms present – pathologic changes occur
Preclinical – sings/symptoms not yet present
Subclinical – signs/symptoms will never become apparent
After signs/symptoms have improved during convalescent phases
Clinical stage: when signs/symptoms appear (usual time of diagnosis)
Recovery, Morbidity (illness), or Mortality (death)
Carrier – doesn’t appear ill but has the infection
Epidemiologic triangle
Shows relationship b/w these 3 as a function of TIME (latency period + duration) AGENT (causes disease)
Microbes; risk factors
ENVIRONMENT (external factors that cause/allow the disease to spread
Contaminated water; blood
Weather, population density, geography
HOST (personal characteristics of those affected by the disease)
Organisms, usu. Human or animals, exposed to and harboring a disease
Can be the one sick OR the one that transmits infection
Consider age, gender, race, job, immunity, behaviors
Modern Epidemiology Triangle:
Risk factors: pysch/envir/behavioral/cult/eco
Groups of populations
Causative factors
Goal of epi: break the triangle to prevent disease or control its spread ID & control risk factors
Disease Occurrence
Outcome: refers to a particular disease under study it’s the dependent variable
Exposure: risk factors; independent variables might affect the outcome
Descriptive epidemiology: the pattern of disease occurrence from the perspectives of person, place, & time = First process in understanding impact of a disease
PERSON
Study population = group being studied
PLACE
Causality: determining the cause of a disease
Screening test: test given to people who have no symptoms to check for the presence of a particular disease
Natural History of Disease: the course of disease if left untreated
Latency period: time from start of disease process until signs/symptoms appear
(Incubation period: time b/w infection & clinical disease)
Nonclinical stage: no signs/symptoms present – pathologic changes occur
Preclinical – sings/symptoms not yet present
Subclinical – signs/symptoms will never become apparent
After signs/symptoms have improved during convalescent phases
Clinical stage: when signs/symptoms appear (usual time of diagnosis)
Recovery, Morbidity (illness), or Mortality (death)
Carrier – doesn’t appear ill but has the infection
Epidemiologic triangle
Shows relationship b/w these 3 as a function of TIME (latency period + duration) AGENT (causes disease)
Microbes; risk factors
ENVIRONMENT (external factors that cause/allow the disease to spread
Contaminated water; blood
Weather, population density, geography
HOST (personal characteristics of those affected by the disease)
Organisms, usu. Human or animals, exposed to and harboring a disease
Can be the one sick OR the one that transmits infection
Consider age, gender, race, job, immunity, behaviors
Modern Epidemiology Triangle:
Risk factors: pysch/envir/behavioral/cult/eco
Groups of populations
Causative factors
Goal of epi: break the triangle to prevent disease or control its spread ID & control risk factors
Disease Occurrence
Outcome: refers to a particular disease under study it’s the dependent variable
Exposure: risk factors; independent variables might affect the outcome
Descriptive epidemiology: the pattern of disease occurrence from the perspectives of person, place, & time = First process in understanding impact of a disease
PERSON
Study population = group being studied
PLACE