Epidemiological Triangle PDF

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Summary

Ann-Marie Matteucci, PhD...

Description

Epidemiological Triangle

Agent: ● ● ● ● ● ●

“What”

The microbe that causes the disease. Disease- causing microbes are bacteria, virus,fungi, and protozoa (a type of parasite). Bacteria: very small but larger than a virus. Can reproduce by themselves. Can be treated with antibiotics. Viruses: Smaller. Do not reproduce but can take over the reproduction of existing cells. Fungi: Plants-like but do not make their own food. Protozoa: Parasites

Host: “Who” ●

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Hosts are organisms, usually humans or animals, which are exposed to and harbor a disease. ○ The host can be the organism that gets sick, ○ As well as any animal carrier that may or may not get sick. Different people can have different reactions to the same agent. (example chickenpox in adults vs. children)

Environment: “Where” The environment is the favorable surroundings and conditions external to the host that cause or allow the disease to be transmitted. Examples:

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dirty water. human blood. warm temperature the season of the year

Vehicle of Transmission: “How” The vector/fomite is how the host and the agent interact in the environment. ● A mosquito is the vector for malaria ● Tick is the vector for Lyme Disease ● A doorknob, dollar bill, or table top might be a fomite.

Time Incubation: period of time between when the host is infected and when disease symptoms occur. Duration: amount of time a person is sick before death or recovery occurs. Threshold of an epidemic. Time it takes between the first case and an epidemic in a population....