INFECTION Flashcards
Invasion and multiplication of
pathogenic microorganisms in a
bodily part or tissue, which may
produce subsequent tissue injury
and progress to overt disease
through a variety of cellular or
toxic mechanismsf
INFECTION
Infection Cycle
Infectious Agent
Reservoir
Portal of Exit
Mode of Transmission
Portal of Entry
Susceptible Host
A pathogen brings disease
to its host.
Infectious Agent
• Another name for a
pathogen is an , as they cause
infections .
Infectious Agent
• As with any organism,
prioritize survival and reproduction .
Pathogens
• an infectious agent is the
habitat in which the agent normally lives, grows , and multiplies .
Reservoir
• are the starting point : Think of a
reservoir as the home or breeding ground for the pathogen .
Reservoirs
• The pathogen needs to move from the reservoir to a new individual (the host) to cause infection .
Transmission to hosts: (reservoir)
• Common reservoirs :
humans (carriers), animals, soil, water, and medical equipment.
It refers to any route that the pathogen can leave the reservoir.
Portal of Exit
This depends entirely on the characteristics of the reservoir.
Portal of Exit
In humans, the main portals of exit include
Alimentary: vomiting,
diarrhea, saliva.
It refer to how an infectious agent, also called a pathogen, can be transferred from one person, object, or animal, to another.
Mode of Transmission
touch and droplet
direct contact
airborne, fomite and vector
indirect
Pathogens enter a new host through breaks in the skin, mucous membranes, or by inhalation or
ingestion.
Portal of Entry
Pathogens can enter through the
mouth and be ingested, lea ding to
infections in the stomach or intestines.
Portal of Entry
Examples include foodborne illnesses like Salmonella and cholera .
Portal of Entry
The final link in the chain of
infection is a susceptible host.
Susceptible Host
People with weakened immune
systems, like hospital patients,
elderly individuals, or healthcare
workers, are more vulnerable.
Susceptible Host
Factors increasing susceptibility:
stress, fatigue, poor nutrition, or
pre-existing illnesses.
Susceptible Host
