Theories of Disease Flashcards
T or F. Disease and other health events do not occur randomly in a population
T
T or F. Risk disease is equal to host, agent and environment.
F
Identify risk of disease
hyperdynamic responses e.g. more likely to develop hypertension/ CV diseases
stress (host)
Identify risk of disease
exposure and vaccination
immunity (host)
identify risk of disease
elderly people are more prone to various infections
age (host)
Identify risk of disease
different strains have different effects (e.g. omicron strains are more likely to spread while the alpha-beta strains are more potent)
virus strains (agent)
Identify risk of disease
allergies
season (envi)
Risk of disease
better results; universal health care
politics (environment)
How did they work together to affect O?
B is a proxy for A as a risk factor for O
How did they work together to affect O?
A and B are overapping risk factors for O
How did they work together to affect O?
both are independent risk factors
How did they work together to affect O?
B mediates the effect of A on O
How did they work together to affect O?
A moderates the effect of B on O
T or F. The basic philosophy about the causation of infectious diseases is the presence of a HOST leads to a disease
F (agent)
T or F. The philosophy about the causation is that the agent alone is not sufficient to produce a disease.
T
T or F. diseases results from an imbalance between a disease, agent, and man.
T
T or F. Nature and extent of the imbalance depends on the nature and characteristics of the agent ONLY.
F (host too)
Who created the first recognized criteria for identifying causes?
Henle-Koch’s Postulates
T or F. The agent is not found in other individuals as a non-pathogenic parasite.
T (if it’s not pathogenic, it will not manifest)
T or F. Koch identified causes for all diseases.
F (some)
T or F. one agent to one disease claim is accurate.
F
T or F. The postulates doesn’t directly relate to non-infectious diseases e.g. diabetes or hypertension.
T
T or F. Every exposed individual becomes infected.
F
T or F. all individuals develop the disease because the presence of the agent
F (not all despite the presence of the agent)
T or F. It is not possible to recover infectious agents from all infected individuals/diseases cases (some viruses stay in the cell hence are difficult to isolate)
T
What contribute to the occurrence of diseases?
agent, host, and environment
The epi triad is designed to be like a seesaw with the the agents as the? envi as the? and host as the?
environment as the base and the agents and hosts on the sides
T or F. The epi triad is adequate for non-communicable diseases that appear to have multiple contributing causes
F (cannot be used to explain cardiovascular diseases)
T or F. The epi triangle is best used for infectious diseases, but not all can be explained
T
T or F. The epi triad is enhance to search for understanding noncommunicable disease.
F (communicable)
a balanced teeter is known to be in its equilibrium state, signifies everything is?
dead eme healthy
What does the imbalance imply if its towards the agent?
the agent has more of an ability to cause a disease
What does the imbalance imply if its towards the host?
increased amount of ways a person is susceptible to a disease
What will the triad become if person A is not sleeping properly, eating healthily, and consuming numerous of junkfood?
towards the host
plays a key role in how the agent and host are affected by a disease, where it is likely to spread, and its current location
environment
→ de-emphasizes the agent as the sole cause of disease while emphasizing the interplay of physical, biological, and social environment; also brings genetics into the mix
→ debunked the triad
Wheel of Causation (Mausner & Kramer, 1985)
→ like the wheel of causation, it de-emphasizes the agent in explaining the disease
→ provides multifactorial causes that traverse various pathways
→ can be highly intricate and complex
→ used for noncommunicable/chronic diseases but can still be applied to communicable diseases
Causation Web
→ when they interact, we can see the disease
venn diagram
→ temporal sequencing
→ used for range of diseases such as evolution of strokes
Path Model
Causal Pies (Rothman, 1976)
any causal factor (agent, host, or environment); casual pathway
● component cause
Causal Pies (Rothman, 1976)
- set of component cases (that may or may not overlap) capable of causing the disease; if all sufficient causes are present, the disease will occur (considered as a causal pathway)
● sufficient cause
Causal Pies (Rothman, 1976)
the component required for the disease to occur
● necessary cause (repetitive)
T or F. In causal pies, a single component cause is rarely a sufficient cause by itself
T
T or F. components may or may not overlap in causal pies.
T
this debunks one agent, one disease
causal pies
T or F. public health actions do not depend on the identification of every disease—prevention can be accomplished by blocking any single component of a sufficient cause through that pathway
T
the causal factor precedes the outcome it is proposed to be causing; exposure first
temporality
if a factor is only associated with a specific disease, it is specific and considered more causal
specificity
dose-response association is supportive of a causal relationship
● biological gradient
finding out if the association is biologically feasible
plausibility
any element, substance, or force whether living or not, the presence or absence of which can initiate or perpetuate a disease process
agent
T or F. An agent can be non-living and borderline.
T
stronger resistance to the effects of drying, heat, and sunlight
encapsulated organisms
requires more time and effort to be destroyed
tetanus and amoeba
how to steralize tetanus and amoeba?
boil for at least 2 minutes
flat, morphology, motility, presence or absence of capsules, whether in the form of spores or cysts or whether they need to be in their vegetative forms to cause infection
physical features
refers to the things needed by the agent to survive Ex. pseudomonas aeruginosa (to eliminate air-loving diseases, lower the oxygen for it to die)
biologic req.
solution to tetanus?
it’s aerobic, needs to be exposed to the air so it won’t survive
ability to gain access and adapt to the human host to the extent of finding lodgment and multiplication
infectivity
measures the ability of an agent when lodged in the body to set up a specific reaction, local or general, clinical or sub-clinical
pathogenicity
severity of the reaction produced (usually measured in fatality)
virulence
ability to stimulate the host to produce antibodies
antigenicity
contaminated inanimate materials or objects (fomites), water, food, blood, serum, plasma, tissues, or organs; any substance serving as an immediate means of transporting and introducing an infectious agent into a host (the agent may or may not have multiplied in/on the vehicle before being transmitted)
vehicle-borne (indirect)
type of vextor-borne:
simple carriage by a crawling or flying insect through soiling of its feet/proboscis or by passage of the organism through the GIT (does not required multiplication/ development of the organism)
mechanical
type of vector borne:
multiplication, cyclic development, or a combination (cyclopropagative) is required before transmitting the agent to the host; an incubation period (extrinsic) is required following the infection prior to the arthropod becoming infective
biological
type of vector-borne:
dissemination of microbial aerosols (suspensions of particles in the air consisting partially or wholly of microorganisms that remain suspended in the air for long periods of time, some retaining and others losing infectivity or virulence) to a portal of entry usually the respiratory tract
airborne
particles in what size are easily drawn into the alveoli?
1-5 micrometer
This airborne are small residues which result from the evaporation of fluid from the droplets
droplet nuclei
may be created purposely by a variety of atomizing devices or accidentally (microbiology labs, abattoirs, rendering plants, or autopsy rooms)—can usually remain suspended for long periods of time
droplet nuclei
small particles of varying size which may arise from soil (e.g. fungus spores from dry soil via wind or mechanical agitation), clothes, bedding, or contaminated floors
dust
an individual exposed to an agent; is susceptible to disease and if a proper condition for parasitism is fulfilled, he affords subsistence/lodgment to the agent and becomes infected
host
T or F. a carrier can be classified as a host
T
point of interest in epidemiology
what happens to the host
delays patients to physicians
🦆
refers to structures of the body which are against injury and disease agents
e.g. spine flexibility, encasement of the brain in a skull, presence of eyelashes and eyebrows, secretion of tears and body fluids for lubrication and cleansing, presence of hairs in nostrils, nostrils pointing downward, and padding by muscles
specific anatomical defenses
reactions of the body to injury (inflammation) and the secretion of adrenaline during stressful periods
specific defenses
a person who possesses specific protective antibodies/cellular immunity as a result of previous infection, immunization, or conditioned by such previous experience as to respond with the production of antibodies following exposure to the specific agent
immunity
attained by maternal transfer
- passive natural
inoculation of specific protective antibodies and is of brief duration (e.g. tetanus and diphtheria antitoxins, rabies hyperimmune serum, antivenin, and gamma globulin)
- passive artificial
attained by infection with or without clinical manifestations
- active natural
inoculation of fractions/products of the infectious agent or the agent itself in its killed, modified, or variant form (vaccinations)
- active artificial
sum total of an organism’s external surrounding condition and influences that affect its life and development
envi
mosquitos at what humidity will they poorly survive?
humidity of below 60%
