Biology + Human Disease Risk Flashcards
(135 cards)
1
Q
strength of association (Hills Criteria)
A
strong associations are more likely to be causal than weak associations
2
Q
consistency
A
repeated observations of an association in different populations under different circumstances
3
Q
specificity
A
requires that a cause leads to a single effect, not multiple effects.
4
Q
temporality
A
the necessity that the cause precedes the effect in nature
5
Q
biologic gradient
A
refers to the presence of a uni-directional dose-response curve
Ex: more smoking = more carcinogenic exposure
6
Q
plausability
A
refers to the biologic plausibility of the hypothesis;
often flawed
7
Q
coherence
A
implies that a cause and effect interpretation for an association does not conflict with what is known of the natural history and biology of the disease
8
Q
The Epidemiologic Triangle
A
models the relationship between:
agent - host - environment
9
Q
Chain of Infection
A
Agent - Reservoir - Portal of Exit - Mode of Transmission - Portal of Entry - Susceptible Host
10
Q
Agent
A
causes disease
ex: bacteria, viruses, parasites
11
Q
Reservoir
A
habitat where agent normally lives, grows, and multiples
ex: humans, animals, environment (soil, water)
12
Q
Zoonosis
A
an infectious disease that is transmissible under natural conditions from vertebrate animals to humans
13
Q
Portal of exit
A
path by which an agent leaves the host
ex: mouth, cuts, urine or stool
14
Q
Mode of Transmission
A
transfer of agent from reservoir to a host
Direct -or- Indirect
15
Q
Direct transmission
A
direct contact (person or soil)
droplet spread (aerosols produced by sneezing, coughing, or talking)
16
Q
Indirect transmission
A
airborne (dust or droplet suspension),
vehicles (food, water, blood, fomites)
vectors (mosquitos, fleas, ticks)
17
Q
portal of entry
A
manner in which agent enters a susceptible host;
dermal, transplacental, oral, respiratory/inhalation
18
Q
susceptible host
A
depends on genetics, immunity, or other determinants of health
19
Q
Louis Pasteur
A
proved that germs caused disease (Germ Theory);
created first vaccines for rabies and anthrax
invented technique of treating milk to stop bacterial contamination (pasteurization)
20
Q
Koch’s postulates
A
4 criteria to establish a causal relationship between agent and disease
anthrax; tuberculosis; later generalized to other diseases
Not all 4 postulates is required to demonstrate causality
21
Q
Koch postulate 1
A
- agent must be found in all organisms with the disease, but not in healthy organisms
22
Q
Koch postulate 2
A
- agent must be isolated from a diseased organism and grown in culture
23
Q
Koch postulate 3
A
- cultured agent should cause disease in a healthy organism
24
Q
Koch postulate 4
A
agent must be re-isolated and matched with original agent
25
mechanical vector transmission
living organism carries an agent from one host to another, but not as an infection
26
biological vector transmission
living organism carries an agent from one host to another as an infection
27
vehicle transmission
food, water, blood, fomites;
non-living item passively carries agent
28
fomite
inanimate objects that become contaminated with the agent
classical example: park water fountain
29
malaria biological vector
anopheles mosquito
30
break-bone/dengue fever biological vector
Aedes aegypti mosquito
31
yellow fever biological vector
Aedes aegypti mosquito
32
west nile fever biological vector
culex mosquito
33
west nile fever reservoir
birds
34
zika biological vector
Aedes aegypti mosquito
35
trachoma mechanical vector
housefly
36
plague biological vector
flea
37
lyme disease biological vector
tick
38
rocky mountain spotted fever biological vector
tick
39
sleeping sickness biological vector
tsetse fly
40
leishmaniasis biological vector
sandflies
41
river blindness biological vector
black flies
42
guinea worm biological vector
water fleas
43
malaria causative agent
plasmodium (protozoan parasite)
44
break-bone/dengue fever causative agent
dengue virus
45
yellow fever causative agent
yellow fever virus
46
west nile fever causative agent
west nile virus
47
zika causative agent
zika virus
48
trachoma causative agent
chlamydia trachomatis
49
plague causative agent
Yersinia pestis
50
lyme disease causative agent
borrelia burgdoferi
51
rocky mountain spotted fever causative agent
rickettsia rickettsii
52
sleeping sickness causative agent
trypanosoma bruceii
53
Japanese encephalitis biological vector
culex mosquito
54
Japanese encephalitis causative agent
Japanese encephalitis virus
55
SEIR Model
Susceptible, Exposed, Infected, Recovered
models progress of epidemic; not the most accurate predictors, but helpful in identifying drivers of infection
56
surveillance
monitors disease trends; identifies epidemics or new syndromes; planning public health policy; evaluating public health policy/intervention
57
passive surveillance
providers or labs report cases to health departments;
most common b/c efficient, simple and inexpensive, is continuous
cons: incomplete data due to underreporting
58
active surveillance
health department contacts providers and labs requesting case info.
Pro: More complete data; capture more cases
cons: expensive and time consuming
59
Epidemic prevention strategies
pasteurization, disinfection, barrier methods, antibiotics, quarantine, vaccination
60
How vaccines work
trigger the body's adaptive immune system (antibody production) to target a specific agent
61
acquired immunity
immunity that develops during your lifetime
62
active immunity
develops in response to a direct infection
natural: actual infection
artificial: vaccination
63
passive immunity
develops after receiving antibodies from someone or treatment
natural: from mother through breast milk
artificial: treatment (gamma globulin injection or infusion)
64
herd immunity
resistance within a population to a certain infection
different thresholds for different diseases
higher infectious disease require higher thresholds
65
antigenic drift
minor change within genes
ex: point mutations in seasonal flu viruses
occurs in both influenza A & B viruses
may cause epidemics
66
antigenic shift
major change within genes, creates a new subtype
ex: exchange of gene segments
occurs in ONLY influenza A
may cause pandemic
67
disease is caused by:
complex interactions between genes and environment
68
demographic transition
high birth and death rates to low birth and death rates
agricultural to industry
infectious to chronic diseases
69
congenital defects
defects present at birth
70
What is part of the recommended uniform newborn screening panel?
- metabolic disorders;
- endocrine disorders;
- hemoglobin disorders;
- hearing loss
71
most genetic conditions screened for in newborn panels follow _____.
an autosomal recessive pattern of inheritance
72
teratogens
agents that induce defects during prenatal development;
half are unknown
73
teratogens: 3 types
1. ionizing radiation
2. chemicals
3. pathogens
74
teratogen: ionizing radiation (2)
gamma rays
x-rays
cause microcephaly or intellectual disabilities
75
teratogen: chemicals (5)
- Accutane: birth defects
- Alcohol: fetal alcohol syndrome
- Cigarette use: LBW, stillbirth, miscarriage
- Dioxin: linked to cancer
- Thalidomide: absence of long bones
76
teratogens: pathogens (3)
- rubella: congenital defects
- syphilis: microcephaly or intellectual disabilities
- toxoplasmosis: stillbirth, miscarriage, developmental disabilities
77
most teratogens affect the embryo during _____.
organogenesis
78
currently the most common cause of unintentional deaths for adults in the US?
unintentional poisoning; drug abuse
79
Clean Air Act
requires EPA to set National Ambient Air Quality Standards;
regulated vehicle emissions
80
National Ambient Air Quality Standards (NAAQS)
6 primary criteria air pollutants:
1. sulfur dioxide
2. nitrogen oxides
3. carbon monoxide
4. ozone
5. lead
6. particulate matter
81
sulfur dioxide (NAAQS)
acid rain;
linked to respiratory effects
affects asthma
82
nitrogen oxides (NAAQS)
smog, acid rain;
linked to respiratory effects;
affects asthma
83
carbon monoxide (NAAQS)
reduces oxygen in body tissue;
affects cardiovascular conditions
84
ozone (NAAQS)
causes airway irritation, coughing, difficulty breathing;
affects asthma and COPD
85
lead (NAAQS)
linked to neurological defects;
86
particulate matter (NAAQS)
smaller than 10 micrometers;
linked to respiratory effects;
affects asthma
87
natural ozone
O3; found in stratosphere;
| absorbs most of sun's UV radiation
88
ground-level ozone
principal component of smog;
causes aging lung tissue and breathing problems
89
How climate change affects public health
- warm winters and hot, wet summers lead to increase vector borne diseases
- increased rain and flooding lead to increased mosquitos
- higher CO2 levels lead to increased pollen which increases asthma rates
90
greatest driver of climate change
greenhouse gases
- created by humans
91
greenhouse gases (5)
1. carbon dioxide
2. methane
3. nitrous oxide
4. ozone
5. water vapor
92
non-point source pollution
unclear, indirect source
93
point-source pollution
clear, direct source;
runoff
94
organophosphates
widely used in insecticides
95
chloroflurocarbon
volatile organic compounds
96
EPA regulates the following pathogens in water sources:
- cryptosporidium
- giardia lamblia
- legionella
- enteric viruses
97
Steps in Water Treatment
1. Coagulation + Flocculation
2. Sedimentation
3. Filtration
4. Disinfection
98
Coagulation + Flocculation
- chemicals with + charge are added to water;
- neutralizes - charge of dirt
- causes particles to bind with chemicals and form larger particles called floc
99
Sedimentation
floc settles to the bottom of the water due to weight
100
Filtration
clear water above settled floc passes through filters
101
Disinfection
chlorination kills remaining parasites, bacteria, viruses
102
Legionnaire's Disease causative agent
legionella pneumophila (bacteria)
103
Legionnaire's Disease source
contaminated water that contained the bacteria
104
legionella pneumophila (bacteria) causes 2 disease
1. Legionnaire's
| 2. Pontiac River Fever
105
cryptosporidium can become a problem in water supplies because _____.
it can survive the chlorine treatment process
106
Danger Zone
40F to 140F
107
Hemolytic Uremic Syndrome is caused by _____.
E. coli strain 0157:H7
108
Pregnant women are 10 time more likely to become infected with _____, which may cause _____.
Listeria;
may cause miscarriage, stillbirth, or preterm labor
109
Common pathogens associated with chicken (3)
1. salmonella,
2. campylobacter,
3. Listeria
110
Common pathogens associated with fish (2)
1. scombroid toxin
| 2. ciguatoxin
111
Common pathogens associated with produce (2)
1. salmonella
| 2. Listeria
112
HACCP
Hazard Analysis Critical Control Point
system for reducing the risk of safety hazards in food
113
HACCP Steps:
1. Conduct hazard analysis
2. identify the critical control point
3. establish critical limits
4. establish monitoring procedure
5. establish corrective action
6. establish record keeping procedures
7. establish verification procedures
114
The Love Canal
Entire town was relocated when hazardous waste was discovered to be disposed below the town.
high rates of miscarriage, birth defects, and cancer
near Niagara Falls in 1952
115
Superfund
created and administered by the EPA;
responsible parties must assume liability for the clean up of environmental hazards they cause
116
Superfund site
any land contaminated by hazardous waste and identified by the EPA as a candidate for cleanup due to risk to human health
117
In the U.S., which is the largest source of radiation dose to the general public?
radon gas
118
toxicology
study of how chemicals cause injury to living cells
119
dose
amount of chemical in the body
120
risk
probability that harm will occur
= toxicity x exposure
121
acute toxicity
one time exposure causes systemic damage
ex: hydrogen sulfide exposure
122
chronic toxicity
long-term, low-level exposure to chemicals causes harmful systemic effects
ex: asbestos exposure
123
dose-response curve
assumes higher dose = greater
effects
exception: carcinogens (no safe threshold)
124
LD50
dose level at which 50% of the test population will die
125
LD0
dose level with no deaths
126
Toxic Substances Control Act (TSCA)
mandated safety and health data on chemicals;
required EPA to regulate substances that pose a risk to human or environment health
127
Clean Water Act
formerly the Water Pollution Control Act;
Established national standards for waterways and set limits on pollutant discharges.
128
Comprehensive and Environmental Response Compensational and Liability Act (CERCLA)
created superfunds to provide clean up of existing inactive and abandoned hazardous waste sites
129
Federal Water Pollution Control Act in 1972
was later renamed to Clean Water Act of 1977;
Established national standards for waterways and set limits on pollutant discharges.
130
Safe Drinking Water Acts
regulated public drinking water systems;
allowed EPA to set maximum contaminant levels for water pollutants in drinking water
131
Comprehensive Air Quality Act of 1967
1st attempt to develop regional approach for air pollution control through Air Quality Control Regions;
oversight of air quality was at state level
132
Clean Air Act (1970)
moved oversight of air quality from state to federal level EPA
133
Resource Conservation and Recovery Act
prevents hazardous waste problems at active sites;
mandated cradle-to-grace tracking system
134
Community Right-to-Know Act
private and public facilities are required to report publicly their waste production for hazardous wastes
135
Hazardous materials transportation act
provided guidance on the transportation of hazardous materials;
overseen by Department of Transportation;
states can set more stringent provisions
