Health Surveillance I Flashcards
Health Surveillance
System of close observation of all aspects of the occurrence and distribution of a communicable disease through systematic collection, orderly consolidation and analysis, and prompt dissemination of all relevant data
Communicable Disease
infectious disease or infestation transmitted from one person/animal to another
Descriptive Epidemiology
uses person, place, and time variables to describe the disease patterns
Analytic Epidemiology
examines complex relationships among determinants of disease
Which types of epidemiology determines why disease rate is lower is one population than another?
analytic
Parts of the Epidemiological Triangle
- Agent
- Host
- Environment
True or False: Changing environment factors can reduce communicable disease risk
True
Reservoir
location where an agent lives and reproduces under normal circumstances
Source
location from which the organism is immediately transmitted to the host
Web of Causation
illustrates the complexity of the interaction of risk factors that leads to chronic disease
Which epidemiological model is useful in the development of interventions?
web of causation
Risk
the likelihood that health people exposed to a specific factor will acquire a specific disease
Rate
- measures the frequency of health event in a defined population in a specific period of time
- used to make comparisons
Calculating a Rate
Numerator: # of Events
Denominator: population size @ specific time period
multiplied by 1,000
Morbidity Rate
the extent of illness, injury, or disability in a defined population
Incidence Rate
describes the new cases of a disease or condition in a community over a period of time
What are incidence rates used for?
detecting and monitoring acute disease
Attack Rate
incidence rate that documents the number of new cases in those exposed
Prevalence Rate
describes the number of ALL cases of a specific disease in a population in a given point in time
What influences the prevalence rate?
- incidence rate (# of new cases)
- duration of the disease/condition
What happens to the prevalence rate when the incidence rate or duration of the disease/condition goes up?
increases
How do epidemiologists collect data for mortality rate?
Death certificates that are filed in the state where the death occurred
Mortality Rate can be broken down into…
- crude death rate
- age-specific
- sex-specific
- cause-specific
Infant Mortality Rate
includes all deaths of children from the moment of birth to the 365th day of life
Five Characteristics of an Infectious Agent
- infectivity
- pathogenicity
- virulence
- toxicity
- antigenicity
Infectivity
ability to enter and multiply in a host
Pathogenicity
ability to produce a specific clinical reaction after the infection occurs
Virulence
ability to produce a severe pathological reaction
Toxicity
ability to produce a poisonous reaction
Antigenicity
ability to stimulate an immunological response
Natural Immunity
innate; what you’re born with
Acquired Immunity
gained by a previous natural exposure
Active Immunity
administration of an antigen and the production of the antibody by the host
Passive Immunity
transfer of an antibody from an immunized person to a non-immunized person
Herd Immunity
the immunity of a group/community
Vertical Transmission
passed from parent to infant through milk, placenta, sperm, or contact with vaginal canal at birth
Horizontal Transmission
person-to-person spread
Direct Transmission
immediate transfer of an infectious agent from an infected host or reservoir through physical contact
Indirect Transmission
infection spread through indirect contact with a vehicle (food, water, fomites)
Vector-borne Transmission
carriers of an infectious agent (Malria, Lyme Disease, Ebola)
Airborne Transmission
infection spread through contaminated droplets in the air (TB, common cold, influenza, rubella, etc.)
Chain of Transmission
Reservior (w/ portal of exit)
Mode of Transmission
Susceptible Host (w/ portal of entry)
Stages of Development of Disease
- infection
- incubation period
- disease
- communicable period
Development of Disease: Infection
entry, development, and multiplication of the infectious agent in a susceptible host
Development of Disease: Disease
showing symptoms caused by the agent; one possible outcome
Development of Disease: Incubation Period
interval between the invasion of the infectious agent and the first signs and symptoms of disease
Development of Disease: Communicable Period
interval during which an infectious agent may be transferred directly or indirectly from one infected person to another
Endemic
disease is constantly present in a given area or population
Epidemic
greater-than-normally expected occurrence of disease in a community or region
Outbreak
similar to epidemic, but in a more limited geographic area and affecting a smaller amount of people
Pandemic
worldwide epidemic affecting large populations
Statistics on Food Outbreaks
~1/6 Americans (48 million) become ill from food borne pathogens every year
~128,000 are hospitalized
~3,000 die
