The Epidemiology Triangle
The Epidemiology Triangle model is based
On the infectious disease model
Active carrier
Individual who has been exposed to and harbors a disease-causing organism (pathogen) and who has done do far some time, even though they may have recovered from the disease
What is epidemic
When an increase in the number of cases of disease occurs above what is normally expected for a given time and place
What is fomite
Objects such as clothing, towels, and utensils that can harbor a disease agent and can transmit it
Primary prevention
Effort to prevent a disease or disorder before it happens
What is the agent
The agent is the cause of the disease
Convalescent carrier
Individual that harbors a pathogen and who, although in the recovery phase of the course of the disease, is still infectious
What is pandemic
An epidemic affecting or attacking the population of an extensive region, county, or continent
What is vector
An invertebrate animal (tick, mite, mosquito) that can transmit an infectious agent to humans
Active primary prevention
Behavior change on the part of the individual that prevents a disease or disorder before it happens (exercising, not smoking)
What is the host
The host is a human or an animal that is susceptible to the disease.
Healthy or passive carriers
Individual who have been exposed to and harbor a pathogen but have not become ill or show any of the symptoms of the disease
What is endemic
The ongoing, usual, or constant presence of a disease in a community or among a group of people
What is reservoir
The habitat in or on which an infectious agent lives, grows, and multiplies and where it depends for its survival in nature
Passive primary prevention
Does not require behavior change on the part of the individual in order to prevent a disease or disorder from occurring (eating vitamin-enriched foods, drinking fluoridated water)
What is the environment
The environment includes those surroundings and conditions external to the human or animal that cause or allow disease transmission
Incubatory carrier
Individual exposed to and who harbor a pathogen, are in the beginning stages of the disease, are showing symptoms, and can transmit the disease
Common-source epidemics
Arise from a specific source
What is zoonosis
An infectious organism in vertebrate animals (rabies, anthrax) that can be transmitted to humans through direct contact, a fomite, or a vector
Secondary prevention
Activities aimed at health screening and early detection in order to improve the likelihood of cure and reduce the chance of disability or death
What is time
Time, which represents the incubation period, life expectancy of the host or the pathogen, and duration of the course of the illness or condition
Intermittent carrier
Individual who has been exposed to and harbors a pathogen and who can spread the disease at different places or intervals
Propagated epidemics
Arise from infections transmitted from one infected person to another
What is vehicle
An inanimate intermediate involved in the transmission of a pathogen from an infected person or reservoir to a susceptible host
Tertiary prevention
Efforts to limit disability by providing rehabilitation where disease, injury, or a disorder has already occurred and caused damage