Case concepts of epidemiology:
Case:
Person in population who has been identified as having a particular disease, disorder, injury, or condition.
Epidemic
Similar to an outbreak but usually from a common source and spreads host to host.
Carrier
contains, spreads, or harbors an infectious organism.
Direct transmission:
the interrupted and immediate transfer of infectious agents from one person to another.
Primary Prevention
Preventing disease or disorder before it happens.
Primary case:
The first disease case in the population.
Pandemic
an epidemic that affects or attacks the population of an extensive region, country, or continent.
Active carrier
Individual who has been exposed to and harbors a disease causing organism and who has done it for some time.
Indirect transmission:
agent is transferred or carried by some intermediate item, organism, means, or process to a host, causing disease.
Active primary prevention:
Requires behavior change in the individual.
Secondary case:
Person that becomes infected as a result of the primary case.
Common-source
an epidemic that arises from a specific source.
Healthy/Passive carriers
Individual who has been exposed to and harbors a pathogen
Airborne transmission
Droplets or dust particles carry pathogens to host and cause infection.
Passive primary prevention:
No change on the individual required.
Suspect case
Individual who has all the signs and symptoms of a disease as result of contact of the primary case.
Propagated:
Infections transmitted from one infected person to another.
Convalescent carrier
Individual who harbors pathogen and who although in recovery phase of the course of the disease is still infectious.
Vector-borne transmission
arthropod conveys the infectious agent.
Secondary prevention:
Health screening and detection activities used to identify diseases.
Pathogen
any virus, bacteria, fungus, or parasite
Mixed epidemic:
Victims of a common-source epidemic have person-to-person contact with others and spread the disease.
Incubatory carrier
Individual who has been exposed to and harbors a pathogen and who can spread the disease in different places or at different intervals.
Vehicle-borne transmission
inanimate object that conveys an infectious agent to a host.
Tertiary prevention:
Block the progression of a disability by providing rehabilitation when a disease, injury, or disorder has occurred and caused damage