Time between entry of infectious agent and appearance of symptoms
During the Incubation Stage, the infectious agent attacks and multiplies to produce infection. The patient is typically not infectious to others during this stage.
Prodromal Stage
Time from beginning of non-specific symptoms until specific symptoms begin to manifest
In the Prodromal Stage, the infectious agent continues to attack and multiply in the host. A patient may also be infectious to other persons. There is a slight elevation in temperature during this stage.
Acute Stage
Time when the disease is at its highest point and the symptoms can be clinically diagnosed
Declining Stage
Time when the symptoms begin to subside and the patient feels improved, but still cannot return to normal activities
Modes of Transmission
Direct Contact
Indirect Contact
Airborne
Foodborne
Waterborne
Vector-borne
Portal of Entry
Opening allowing the microorganism to enter the host, such as body orifices, mucus membranes, and breaks in the skin
Portals of Entry
Gastrointestinal System
Respiratory System
Urinary and Reproductive Tracts
Breaks in the Skin
Susceptible Host
A person who cannot resist the invading microorganisms
Pathogen
An organism capable of producing a disease
Reservoir
A place where microorganisms can thrive and reproduce, the most common being the human body
Portal of Exit
A way the microorganism can leave the reservoir, such as the nose, mouth, or body fluids
