lecture 17 chapter 19 Flashcards
(148 cards)
1
Q
puerperal fever
A
bacterial infection of uterus
2
Q
_______ led to incidence of puerperal fever dropping to 1/3 previous level
A
washing hands
3
Q
what is epidemiology?
A
the study of distribution and causes of disease in populations
4
Q
epidemiologists collect and compile data about
A
sources of disease and risk factors
5
Q
epidemiologists have expertise in many disciplines including
A
ecology, microbiology, sociology, statistics, and psychology
6
Q
transmitted from one host to another
A
communicable (contagious diseases)
7
Q
communicable disease transmission can be ______ or ______
A
direct, indirect
8
Q
do not spread from host to host
A
non-communicable diseases
9
Q
in non-communicable diseases, microorganisms most often arise from
A
individuals normal microbiota or environment
10
Q
percentage of people who become ill in population after exposure to infectious agent
A
attack rate
11
Q
epidemiologists are more concerned with _______ rather than the absolute number of cases
A
rate of disease (usually cases per 100,000)
12
Q
attack rate reflects
A
infectious dose, immune status of population
13
Q
a measure of the frequency with which new cases of illness occurs among a population during a specified period
A
incidence
14
Q
total number of cases at any time or for a specific period in a given population
A
prevalence
15
Q
prevalence reflects
A
overall impact of disease on society; includes old and new cases, as well as duration of disease
16
Q
incidence is a measure of risk of
A
an individual contracting a disease
17
Q
incidence of disease in a population
A
morbidity
18
Q
contagious disease often have high ______ rate: infected individuals may transmit to several others
A
morbidity
19
Q
overall death rate in population
A
mortality
20
Q
percentage of population that dies from a specific disease
A
case-fatality rate
21
Q
_____ is constantly present in population
A
endemic disease
22
Q
example of endemic disease
A
common cold
23
Q
____: a few cases from time to time
A
sporadic
24
Q
_____: unusually large number of cases
A
epidemic
25
an epidemic can be introduced _____ or ______
agent, endemic disease
26
_____ is a group of cases at specific time and population
outbreak
27
______ is global
pandemic
28
example of pandemic
COVID19, AIDS
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the spread of infectious disease follows a series of steps called
the chain of infection
30
natural habitat of pathogen
reservoir of infection
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parts of chain of infection
reservoir of infectious agent
portal of exit
transmission
portal of entry
susceptible host
32
_____ is critical to disease control
identification
33
pathogen is often easier to control if ______ are the only reservoir
humans
34
clear source of pathogens
symptomatic infections
35
harder to identify, carriers may not notice infection, can spread it to others
asymptomatic infections
36
in carriers, the immune system may be responding to pathogen, ______ expression of symptoms
inhibiting
37
up to ____ of women infected with Neisseria gonorrohoeae are asymptomatic, easily transmit it
50%
38
______ are difficult to control in wild animal populations
non-human animal reservoirs
39
examples of non-human animal reservoirs
plague, hantavirus, Lyme disease
40
______ exist mostly in animals, can be transmitted to humans
zoonoses (zoonotic diseases)
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______ can be significantly more sever in humans; no evolution toward balanced pathogenicity
zoonoses
42
______ are difficult or impossible to eliminate
environmental reservoirs
43
examples of environmental reservoirs
clostridium species; legionnaires' disease
44
body surface or orifice; exit route for pathogen
portal of exit
45
examples of portals of exits
intestinal tract (shed in feces)
respiratory tract (exit in droplets of saliva)
skin (shed on skin cells)
genital pathogens (semen, vaginal secretions)
46
disease transmission types
vertical transmission
horizontal transmission
direct transmission
indirect transmission
47
example of vertical transmission
pregnant mother to fetus in utero; or, mother to infant during childbirth; by breastfeeding
48
example of horizontal transmission
is person to person via air, physical contact, ingestion of food or water, or vector
49
______ involves immediate transfer of infectious agent to portal of entry
direct transmission
50
direct contact
touch (touching, kissing, sexual contact, contact with oral secretions, or contact with body lesions)
51
direct contact is easiest when infectious dose is
low
52
______ considered single most important measure for preventing spread of infectious disease
hand washing
53
some pathogens cannot survive in environment, require ______
intimate sexual contact (treponema palladium, neisseria gonorrhoeae, STDs in general)
54
indirect transmission occurs in several ways, including:
aerosol droplet transmission
airborne
vehicle-borne
vector-borne
55
______ can spread respiratory disease when pathogen-laden droplets are inhaled
aerosol droplet transmission
56
aerosol droplet transmission is minimized by
covering mouth when sneezing
57
aerosol droplets generally fall to ground within a
meter
58
______: respiratory diseases often transmitted by small droplets/particles released while talking, etc. travel further
airborne
59
in airborne disease transmission, ________ remain suspended; inhaled, carry pathogens to lungs
aerosol droplet nuclei (microbes attached to dried material)
60
other airborne particles include
dead skin cells, dust, spores
61
____ increase number of bacteria in air
crowds
62
airborne tranmission is
difficult to control
63
methods to combat airborne transmission
ventilation systems, negative pressure, HEPA filters, face coverings (masks)
64
_______: transmitted by objects, food, water
vehicle-borne
65
_____: inanimate objects
fomites
66
examples of fomites
clothing, keyboards, doorknobs, drinking glasses
67
______ can become contaminated
food and water
68
_______: transfer between foods
cross-contaminations
69
_______ can distribute disease to large numbers
municipal water systems
70
a ______ is a living organism that can carry a pathogen
vector
71
vector-borne transmission are most often _____
anthropoids (mosquitoes, flies, fleas, lice, ticks)
72
______ carries microbe on its body from one location to another
mechanical vector
73
______ also participates in life cycle of pathogen
biological vector
74
vector control programs are important, cost-effective measure in preventing _______
vector-borne diseases
75
______: body surface or orifice, entry route for pathogen
portal of entry
76
respiratory pathogens generally cause disease only when _____
inhaled (nose)
77
intestinal pathogens generally cause disease only when ____
ingested (mouth)
78
_______ is when fecal organisms are transported to mouth and ingested
fecal-oral transmission
79
_____ is the ability to cause disease
virulence
80
virulence includes factors that _____
allow pathogen to attach to host cell, avoid immune defenses, damage host
81
______: number of pathogens introduced; minimum number of pathogens required to produce symptoms
the dose
82
_______: influences extent of spread
the incubation period
83
if few cells enter, immune system may ____
eliminate organism before symptoms appear
84
long ______ can allow extensive spread before first symptoms appear
incubation period
85
_______ comes from previous exposure or immunization
immunity to pathogen
86
_______ protects non-immune individuals in population; >90% immunity typically sufficient
herd immunity
87
______ can overcome herd immunity
antigenic variation
88
aspects of general health
malnutrition, overcrowding, fatigue
89
______ are more susceptible to disease
developing areas
90
____ or ____ people generally more susceptible to disease
very young, elderly
91
immune system less developed in ____
young people
92
immune system ____ in elderly
wanes
93
_____ are less likely to update immunizations
elderly
94
_____ more likely to develop urinary tract infections
women (urethra is shorter, microbes more likely to ascend)
95
______ provides protective antibodies to infant
breastfeeding
96
consumers of _____ are more likely to acquire tapeworm
raw fish
97
natural immunity varies widely among _____
genetic backgrounds
98
lack of _______ on red blood cell gives immunity to Plasmodium vivax
receptor
99
lack of ______ on white blood cell reduces susceptibility to HIV
co-receptor
100
factors that influence the epidemiology of disease
gender, behavioral practices, genetic background, characteristics of the environment, characteristics of the host
101
______ allow survival in damaging conditions
endospores
102
exposure to ______ allows development of resistant organisms
antibiotics
103
_______: data collected during an outbreak to determine possible risk factors for disease spread
descriptive study
104
the person: _________ may all yield clues about risk
age, gender, ethnicity, occupation, personal habits, pervious illnesses, socioeconomic class, marital status
105
the place: _______ might affect transmission
geographic location that helps pinpoint source, yield clues about potential reservoirs, vectors, or boundaries
106
the time: ______ can affect transmission
the season
107
vector-borne diseases are more common in ____ weather
warm
108
________ provides support for labs in the US and abroad; collects data on diseases that impact public health
centers for disease control and prevention (CDC)
109
the CDC collects data on over ____ notable diseases
50
110
public health departments in each state have authority to _____ diseases that must be reported
mandate
111
the world health organization (WHO) has four main functions:
provide worldwide guidance in field of health
set global standards for health
cooperatively strengthen national health programs
develop and transfer appropriate health technology
112
the world health organization provides education and technical assistance to ____ member states
193
113
many diseases reduced through improved _____
sanitation, reservoir and vector control, vaccination, and antibiotic treatment
114
in US, many formerly common diseases are
rare
115
_____ has been eradicated globally; work underway to eradicate measles, polio, dracuncaliasis
smallpox
116
_______: novel or have recently increased in incidence
emerging infectious disease
117
new or newly recognized diseases include _____
Middle East respiratory syndrome (MERS), ebolar, zika
118
disease increasing in incidence include _____ and ______
malaria, tuberculosis
119
example of microbial evolution
vibrio cholerae gained ability to produce capsule; antibiotic resistance can contribute to reemergence of disease
120
changes in human society: ______ relatively new in US allow easy transfer of pathogens such as those that cause colds or diarrhea
day-care centers
121
______ has led to increased contact with reservoirs of disease (Lyme disease; deforestation in Amazon basin)
population expansion
122
(development) dams extend range of _____ by increasing habitat for host snail
schistosomiasis
123
______ has caused food borne illnesses to easily spread
mass production, widespread distribution, and importation of food
124
_______ have caused refugee camps with poor conditions
war and civil unrest: disruption of infrastructure and eradication efforts
125
because of _______, warm temperatures favor reproduction of some arthropods that serve as vectors
climate change
126
healthcare-associated infections (HAIs) acquired while receiving treatment in a _______
healthcare setting such as hospital, therapy center, urgent care facility, or long-term care residence
127
healthcare-associated infections are one of top _____ causes of death in united states
10
128
healthcare-associated infections occur in
dense populations of unusually susceptible people, where the most resistant and virulent pathogens may criculate
129
hospital-acquired ______ affect up to 5% of patients
nosocomial infections
130
acinetobacter baumanii
enviornmental bacterium found on skin of healthy people; causes a variety of HAIs; most strains are multi-drug resistant
131
candida species
yeasts; part of the normal microbiota; common cause of blood stream infections
132
examples of reservoirs of infectious agents in healthcare settings
other patients, some gram-negative rods can thrive in (sinks, ventilators, toilets), healthcare workers, visitors, patient microbiota
133
direct transmission in healthcare settings can happen through ____
healthcare personnel (must be vigilant with hand washing, disinfecting, gloves)
134
indirect transmission in healthcare settings can happen through ____
medical devices (catheters, IV lines, mechanical ventilators, inadequately sterilized invasive instruments)
airborne (reduce with air pressure, careful mopping, HEPA filters)
135
category A agents of bioterrorism
bacillus anthracis (anthrax)
clostridium botulinum toxin (botulism)
yersinia pestis (plague)
smallpox virus
francisella tularensis (tularemia)
viruses that cause hemorrhagic fevers
135
category A agents of bioterrorism
bacillus anthracis (anthrax)
clostridium botulinum toxin (botulism)
yersinia pestis (plague)
smallpox virus
francisella tularensis (tularemia)
viruses that cause hemorrhagic fevers
135
category A agents of bioterrorism
bacillus anthracis (anthrax)
clostridium botulinum toxin (botulism)
yersinia pestis (plague)
smallpox virus
francisella tularensis (tularemia)
viruses that cause hemorrhagic fevers
136
clostridium difficile
toxin-producing strains can cause diarrhea and colitis in people taking antibiotics
137
enterobacteriaceae species
part of the normal intestinal microbiota; cause a variety of HAIs; some are not easily treated because they are resistant to last resort antibiotics
138
enterococcus species
part of the normal intestinal microbiota; cause a variety of HAIs; some have developed antimicrobial resistance
139
pseudomonas species
grow in most, nutrient-poor environments such as the humidifier of a mechanical ventilator; cause a variety of HAIs, including infections of burn wounds; some are multi-drug resistant
140
staphylococcus aureus
many people are carriers; transmissible on fomites; often resistant to a variety of antimicrobial drugs; causes a variety of HAIs
141
urinary tract infections
infections of the bladder or kidneys; most hospital-acquired UTIs are associated with catheter use
142
bloodstream infections
infectious agents in the blood can lead to sepsis, particularly in sick or immunocompromised individuals; hospital cases are often associated with central lines (caterers placed near the heart) that may allow infectious agents to enter the bloodstream directly
143
surgical site infections
barriers such as skin and mucous membranes are breached, increasing vulnerability to infection; normal microbiota from the skin or gastrointestinal (GI) tract are common causes
144
pneumonia
lung infection; in hospitals, many cases are associated with ventilator use; most common cause of death from nosocomial infection in critically ill patients
145
gastrointestinal infections
most hospital-acquired GI infections are due to clostridium difficult; related to antibiotic use
146
other infections
infection sites including skin, eyes, uterus, burns, and others
