Cph 2b And 3 Flashcards
are extrinsic factors
which affect the agent and the
opportunity for exposure.
Environmental factors
intrinsic factors that
influence an individual’s exposure,
susceptibility, or response to a causative
agent.
HOST FACTORS
agent might be
microorganism—virus, bacterium,
parasite, or other microbes. e.g. polio,
measles, malaria, tuberculosis Generally,
these agents must be present for disease
to occur
Infectious Agents
excesses or deficiencies
(Cholesterol, vitamins, proteins)
Nutritive
(carbon monoxide,
drugs, medications)
Chemical angent
(Ionizing radiation,…
Physical angent
is an event, condition, or
characteristic without which the disease
would not have occurred.
Cause
“…a complete causal
mechanism” that “inevitably produces
disease.” is not a single factor, but
a minimum set of factors and circumstances
that, if present in a given individual, will
produce the disease.
A sufficient cause
Each component in a sufficient cause is called
Component cause
A component cause that must be present in every
sufficient cause of a given outcome is referred to as
A necessary cause
The components of a sufficient cause do not need
to act simultaneously; they can act at different
times. True or false?
True
There is no single cause
Causes of disease are interacting
T or F?
True
Pre-exposure period in the natural
history of disease, in which the
individual in the population is
vulnerable or at risk to acquire the
infection.
Stage of susceptibility
Sometimes called a pre-infection
Pathological changes occur but no
obvious recognizable clinical
findings.
Stage of subclinical disease
Has recognizable manifestations
Manifestations of the disease are the
clinical evidence of effects, the signs
and symptoms of disease
Stage of clinical disease
those diseases
caused by biological agents or their
products and are transmissible from one
individual to another
Communicable disease
those
diseases that cannot be transmitted from
one person to another
Non-communicable disease
peak severity of symptoms
occurs and subsides within three months
(usually sooner) and the recovery of those who
survive is usually complete.
Acute disease
symptoms continue longer
than three months, and in some cases, for the
remainder of one’s life; recovery is slow and
sometimes incomplete.
Chronic diseases
the ability of a biological
agent to lodge and grow in a host
Infectivity
an infectious disease
agent’s ability to produce disease
Pathogenicity
a pathogen’s ability to
cause damage to a host; the degree of
damage caused by a microbe to a host
Virulence
factors produced by
microorganisms that enable them to
invade a host; evade host defenses and
evoke disease
Virulence factors
(Epidemiologic triangle)
is the element that must be present
for disease to occur.
Agent