Intro to epidemiology and descriptive Flashcards
what is epidemiology
the study and analysis of the distribution, patters, and determinants of health and disease conditions in a defined population
epidemic
illness/behavior/health related event in excess of normal
pandemic
epidemic that affects the population of an extensive region
endemic
ongoing, usual, or constant presence of a disease in a community
descriptive epidemiology
involves characterization of the distribution of helath-related states or events (person, place, time)
objectives of descriptive epidemiology
- describe public health problem via person, place, time
- communicate public health problem with the use of tables and graphs
- identify who is at greatest risk for selected health-related states or events
- use serveillance methods
- understand how it can improve
what is meant in regards to descriptive data on a person
- age
- sex
- race/ethnicity
- marital and family status
- occupation
- education
what has a strong influence on outcomes
age
what are population pyramids used for
tracking and comparing changes in the population age distributions over time
what are the types of population pyramids
stationary
expansive
constrictive
stationary pyarmid
a population pyramid typical of countries within average fertility and low mortality
expansive pyramid
a population pyramid that is very wide at the base, indicating high birth and death rates
constrictive pyramid
- comes in at the bottom
- population is generally old on average
- long life expectancy
- low death rate
- low birth rate
why is family structure important
- health behavior clusters in family
- genetics
- important to look at intervention approaches as a family unit
how does occupation relate to health outcomes
socioeconomic status, eidcation, risk of injury
what is the healthy worker effect
phenomenon where working people are healthier than non working individuals
analytic epidemiology
involves finding and quantifying associations, testing, hypotheses, and identifying causes of health-related states or events
what does the where question look at
comparisons between or among geographic regions in grops before and after migration adn between twins raised in different settings
what is temporal in relation to time factors
meaning time
- referring to time-related elements or issues
how do epidemiologic investigations take
can range from hours to weeks to years to decades
what is the main driver of surveillance
public health initiatives
what normally comes first descriptive epi or analytic epi
descriptive
what is a cause in regards to epi
a specific event, condition, or characteristic that precedes the health outcome and is necessary for its occurance
how can adverse health outcomes be prevented
by eliminating the exposure vaccinations, quarantines,
is the presence of a given exposure necessary for a specific health outcome and adverse health outcome to occur
no someone exposed to a virus is necessary for the virus to cause infection but not everyone exposed will get infected
risk factor
behavior, environmental exposure, or inherent human characteristic that increases the chance of developing an adverse health outcome
- not sufficient to cause a disease
what are some risk factors
smoking –> cancer, heart disease, stroke, lung, disease, prematur/low birth weight babies
unsafe sex –> STDs, cancer
physical inactivity –> heart disease, hypertension
what are epicurves
different types of distribution that shows who has been infected
what are the three types of epicurves
- point-source/common source
- continuous source
- propagated
type of time trends
- secular trends
- short term trends
- cyclic trends
- seasonal trends
secular time trends
represented long term changes in health-related states or events
short term trends
usually brief, unexpected increases in health related states or events
cyclic trends
represent periodic increases and decreases in the occurrence of health-related states or events
seasonal trend
pattern where rise and fall of disease occurs predictably throughout the year
point source epicurve
- will look like a pyramid
- food outbreaks
- comes from a specific source
continuous source
- from an exposure over a long time
- will have a few infected and then show a long period of infected individuals
what is the time trend of a point source epidemic
individuals are exposed to the same source over a limited time period
- clustering of cases in time with a sharp increase and trailing decline
propagated source
- from infections transmitted from one infected person to another
- will look like multiple separate infected periods (gaps shows incubation period)
- STDs, respiratory infections, etc.
what is the time trend for a continuous source epidemic
exposure is continuous over time
- gradual increase, plateau, then decrease
case
a person in a population who has a disease, disorder, injury, or condition
case definition
standard set of criteria for classifying a person with a health problem
- things like fever, cough, etc.
primary case
the first disease case in the population
index case
the first disease case brought to the attention of an epidimiologist
secondary case
a person who becomes infected after contact with a primary case
suspect case
individuals/group who have signs and symptoms but not diagnoses
probable suspect case
individual has some or all known symptoms
confirmed suspect case
individual has symptoms and a pos test to disease
case severity
how disabiling/debiitating the illness is
what is needed for transmission
a host, an infectious agent, and an environment
what is the host
the individual exposed, its susceptabilty and response to a given infection
what are some factors that influence the liklihood of an individual getting an infection
socioeconomic status, prior exposure, etc.
what is the infections agent
the cause
- a bacteria, fungi, etc.
what is the environment
a factor that influences the opporunity for exposure
- climate change, warm temperatures, humidity, etc.
what are the different words regarding disease transmission
fomite
vector
resevoir
vehicle
fomite
inanimate object that can harbor a pathogen and is capable of being a means of transmission
vector
an invertebrate animal that transmits infection by conveying the pathogen from one host to another
reservoir
is the habitat (living or nonliving) in or on which an infectioys agent lives, frows, and multiplies, and on which it depends for its survival in nature
vehicle
fomite intermediary that conveys the infectious agent from its reservoir to a susceptible host
carrier
human that contains, spreads, or harbors an infectious organism
what are the types of carriers
active carrier
convalescent carrier
healthy carrier
incubatory carrier
intermittent carrier
active carrier
exposed and harbors the pathogen
convalescent carrier
harbors the pathogen, recovery phase
healthy/passive carrier
not ill but exposed and harbors the pathogen
incubatory carrier
exposed, and harbors the pathogen, ability to transmit
intermittent carrier
exposed to and harbors can spread pathogen at different times
what are the different modes of disease transmission
direct
indirect
direct disease transmission
is the uninterrupted and immediate transfer of a pathogen from person to person
indirect disease transmission
occurs when a pathogen is transferred or carried by some intermediate
what are the types of indirect transmission
airborne
vector-borne
vehicle-borne
airborne transmission
droplets or dust carry the pathogen to the host and cause infection
vector-borne transmission
occurs when an arthropod conveys the infectious agent
vehicle-borne
involves an inanimate object that conveys an infection to a host
what is the infectious disease cycle
infectious agent –> resevoir –> portal of exit –> mode of transmission –> portal of entry –> susceptible host
using norovirus how does the infectious disease cycle work
infectious agent –> resevoir (stool) –> portal of exit (secretion of feces) –> mode of transmission (indirect via hands) –> portal of entry (most likely hands) –> susceptible host
what are ways to break the cycle regarding norovirus
stop the portal of entry by washing hands (other conditions wearing PPE), susceptible host by giving vaccines, can kill the virus directly attacking the infectious agent
what are the different levels of prevention
primary, secondary, and tertiary prevention methods
primary prevention
preventing disease or disorders before it happens
secondary prevention
aimed at the health screening and detection activities used to identify disease
tertiary precentions
limiting any disability by providing rehabilitaion when a disease, injury, or disorder has already occurred
efficacy
ability of a program to produce a desired effect among participants in the program compared to those not in the programe
effectiveness
the ability of a program to produce benefits among those who are offered the program
