Risk of Infectious and Communicable Diseases Flashcards
Exam 2
Infectious Disease:
What is it?
Presence and replication of an infectious agent in the tissues of a host, with manifestation of signs and symptoms
Infectious Disease:
Pathogenicity
Pathogenicity— the ability of the agent to produce an infectious disease in a susceptible host.
Virulence
This is a quantitative trait, representing the extent of the pathology caused by a microorganism.
Virulence - What does it express?
Therefore, virulence is a trait expressing the interaction between a pathogen and its host.
Epidemiology of the Infectious Process: The Chain of Infection
Epidemiologic triad
Agent
Host
Environment
Epidemiology of the Infectious Process: The Chain of Infection
The epidemiology of the infectious disease process adds other elements to the epidemiological triad:
The epidemiology of the infectious disease process adds other elements to the epidemiological triad:
a portal of exit for the infectious agent,
a means of transmission,
and a portal of entry to a new host.
Chain of Infection includes:
Infectious agents
Reserviors
Portal of exit
Means of transmission
Portal of entry
Susceptible host
Carrier
A person or animal who harbors an infectious organism and transmits the organism to others while having no symptoms of the disease
Colonization
The presence and multiplication of infectious organisms without invading or causing damage to tissue
Incubation Period
Time period between initial contact with the infectious agent and the appearance of the first signs or symptoms of the disease
Is the following statement True or False?
An infectious disease is not contagious or communicable.
False
Rationale: An infectious disease may or may not be contagious or communicable.
Environment/Reservoirs
Humans
Animals
Plants
Insects
Water
Soil
Mechanisms of Transmission
Direct contact
Indirect contact
Droplets
Airborne transmission
Outbreak Investigation:
What must be established?
Establishing the existence of an outbreak
Outbreak Investigation:
How must cases be described?
Describing cases by person, place, time
Outbreak Investigation:
Common source outbreak—
an outbreak characterized by exposure to a common, harmful substance
Outbreak Investigation:
Propagated outbreak—
Propagated outbreak—outbreak resulting from direct or indirect transmission of an infectious agent from an infected person to a susceptible host; secondary infections can occur
Outbreak Investigation:
Propagated outbreak—What else can occur with this?
secondary infections can occur
Types of Outbreaks include:
Endemic
Epidemic
Pandemic
Types of Outbreaks include:
Endemic
the constant or usual prevalence of a specific disease or infectious agent within a population or geographic area