Final exam - Week 4 Flashcards
1
Q
what is a disease caused by the invasion and growth of pathogenic agents or microbes in a host?
A
infectious disease
2
Q
What is infectious disease synonymous with?
A
communicable disease
3
Q
true or false: infectious disease is always contagious
A
false; may or may not be
4
Q
true or false; IDs are among the leading causes of death
A
true
5
Q
What are illnesses capable of transmission directly or indirectly among humans?
A
contagious
6
Q
What 3 factors comprise the epidemiological triangle of disease? what additional?
A
- host
- agent
- environment
- vector - center
7
Q
What are agent factors associated with?
A
the pathogen causing the infection
8
Q
What are host factors associated with?
A
those internal to the animal or human invaded by the agent that contribute to its susceptibility and infectiousness
9
Q
What are environmental factors?
A
are everything else external to the host and agent that influence the transmission and development of an infectious disease
10
Q
What is a vector?
A
are organisms, usually invertebrate arthropods like mosquitoes and ticks, that transmits a agent from one host to another
11
Q
Host factors that contribute to infectious disease transmission include what?
A
those that effect host susceptibility as well as those that relate to the host infectiousness
12
Q
What does susceptibility include?
A
both host resistance and immunity
13
Q
What role has genome scanning had in ID?
A
they have been able to identify genes associated with specific infectious diseases.
14
Q
What factors are under resistance for susceptibility?
A
- Genetics
- Age/ gender/ancestry
- Pregnancy
- General health
- Nutrition
- Chronic diseases
- Stress
15
Q
what is an innate resistance to a specific antigen or toxin, such as through genetics which we just discussed?
A
natural immunity
16
Q
What does acquired immunity come from?
A
from actual exposure to a specific infectious agent and is further divided into two subcategories, active and passive.
17
Q
When does active immunity occur?
A
occurs when the host stimulates its own antibodies thru exposure to the agent, either through natural exposure or exposure with an immunization
18
Q
When does passive immunity occur?
A
when antibodies are transferred to the host, either through mother to infant or through immune globulin or antitoxin.
19
Q
what is the resistance of a population to the infection because a high proportion of individual members are resistant?
A
herd immunity
20
Q
What 2 things can herd immunity be?
A
- natural due to genetics
2. acquired from past exposure
21
Q
What do immunizations provide?
A
active immunity for the individual and herd immunity for the community.
22
Q
What is the ability of an infected host to transmit infection?
A
infectiousness
23
Q
What is the infected host usually referred to as?
A
as the human or animal reservoir for the infectious agent
24
Q
What are the 3 stages of infection?
A
- latent
- communicable
- incubation
25
What is the latent stage of infection?
begins with exposure and ends when the pathogen begins to shed.
26
Are people infectious during the latent stage of infection?
no
27
What is the communicable stage characterized by?
the shedding of the pathogen
28
what is the progression of the communicable stage?
begins before symptoms and ends after symptoms disappear
29
Is a host infectious during the communicable stage?
yes
30
Only what type of disease has a period of communicability?
contagious disease
31
When does the incubation stage begin and end?
begins with exposure to the agent like the late stage and ends when symptoms appear
32
When is a host frequently infectious?
when they are asymptomatic
33
For diseases like tetanus and Lyme disease, which are not infectious, what is unique about them?
they have an incubation and disease period, but latent and communicability periods do not apply
34
What are organisms capable of producing infection in a host?
infectious agents
35
What are the 4 infectious agents?
1. bacteria
2. viruses
3. parasites
4. fungi
36
What are the 3 ways an agent interacts with its host?
1. infectivity
2. pathogenicity
3. virulence
37
What is infectivity?
refers to the ability of an agent to enter, survive and multiply in a host or their power to invade and infect large numbers of people.
38
What is infectivity a characteristic of? infectiousnessness?
a. agent
| b. host
39
What is the agents ability to cause disease and refers to the proportion of infected people who actually develop the disease?
pathogenicity
40
Infectious agents that cause a large percentage of subclinical infections are said to have what?
low pathogenicity
41
What is the ability to produce a severe pathological reaction and refers to the proportion of infected people who died or become severely disability?
virulence
42
How is the virulence of a disease often measured?
in terms of mortality rate
43
What are the environmental factors in the epidemic triangle?
all those that are external to the animal or human host and the agent
44
What can environmental factors be?
1. physical
2. biological
3. social
4. cultural
45
What are examples of environmental factors that can impact infectious disease?
1. Location (institutions, geography, spectrum of disease)
2. Non-living reservoirs (soil, water)
3. Climate change and extremes
4. Insects and animals
5. Body fluids
6. Crowding, education, resources and access to care
7. Norms, health beliefs, health behaviors
46
What is an endemic?
occurring at a consistent, expected level in a defined and often limited area geographic area
47
What is an outbreak?
unexpected occurrence or increase; limited geographical area; limited period of time.
48
What is an epidemic?
unexpected occurrence or increase; in a defined but larger geographical area; extended period of time
49
What is a pandemic?
epidemic that has spread over several countries or continents, usually affecting a large number of people.
50
What is the means by which an agent is transmitted from one host or inanimate reservoir to a host?
modes of transmission
51
What are modes of transmission impacted by?
1. host
2. agent
3. environmental factors
52
What is vertical transmission?
the passing of the infection from parent to offspring via sperm, placenta, milk, or contact in the vaginal canal at birth
53
What is horizontal transmission?
the spreading of infection from a host or reservoir to a person and includes direct, indirect, airborne and vector transmission
54
true or false; horizontal transmission is limited to contagious diseases.
false; it is not
55
How do direct transmissions occur?
by immediate transfer of pathogen from an infectious host to a susceptible host.
56
What does direct transmission include?
includes touching, sexual intercourse, kissing,, biting.
57
When does indirect transmission occur?
occurs when the infectious agent is transported via contaminated inanimate reservoirs such as air, water, door knobs, counters, eating and drinking utensil, personal care products and medical supplies such as shares.
58
How does direct transmission occur?
occurs by immediate transfer of pathogen from an infectious host to a susceptible host and includes touching, sexual intercourse, kissing,, biting.
59
Can droplet be vertical and horizontal?
yes, but is usually horizontal
60
When does indirect transmission occur?
occurs when the infectious agent is transported via contaminated inanimate reservoirs such as air, water, food, door knobs, counters, eating and drinking utensil , personal care products and medical supplies such as sharps
61
What is a type of indirect transmission which occurs through droplet nuclei or dust particles?
airborne transmission
62
How is airborne different from droplets?
much smaller and can travel farther and also remain suspended for long periods before they are inhaled by a host
63
What are vectors?
are organism, usually invertebrate arthropods like mosquitoes and ticks, that transmits a pathogen from an infectious to susceptible host.
64
How can infectious diseases which are not contagious be transmitted?
direct or indirect mode of transmission.
65
What are 4 major public health problems?
1. TB
2. valley fever
3. malaria
4. rabies
66
What are the two types of TB conditions?
1. latent TB infection
| 2. active TB infection
67
What are people with latent TB?
they are infected with the bacteria and do not have symptoms
68
What is the agent of TB?
1. A bacteria - mycobacterium tuberculosis
| 2. MDR TB and XDR TB
69
Finish the sentence: people with latent TB are hosts during the...
latent period of infectiousness and are not contagious
70
What are host factors associated with increased risk of TB?
Genomics, race and age can impact risk for infection.
71
What is the most significant host factor for TB disease?
positive HIV status, although all people with weakened immune system are at increased risk
72
What are environmental risk factors for TB?
Living/working in a congregate living conditions; refugee camps; working with high risk populations; living/traveling in countries with high TB rates; close contract with someone who has TB disease
73
How is TB spread? Not spread?
spread by droplets nuclei, not saliva
74
What is the primary strategy used in the prevention and control of TB?
early detection and treatment of latent TB in at risk populations and health care workers
75
How is screening usually done for TB?
skin test or blood test
76
How is TB disease treated?
taking several different drugs for 6 to 9 months
77
What is the most effective strategy to treat for TB disease?
Directly observed therapy or DOT
78
What is DOT or eDOT?
Patient takes the medicine while the health care worker watches. Many health department are now using eDOT, which is using technology to monitor adherence to ingesting the prescribed medication either in real time or recorded.
79
What are other important health care facility strategies for TB control?
special masks for HCWs which filter out the tiny droplet nuclei that are frequently pretty dense in the TB patients room; having TB patients use a mask; and caring for TB patients in reverse isolation rooms to reduce the amount of TB in the area.
80
true or false; the TB vaccine is used a lot in the US
false
81
When should the TB vaccine be used?
should be considered for only very select people who meet specific criteria
82
What is coccidiodymosis?
valley fever; a respiratory infection caused by the inhalation of fungal spores that live in soil and which have become airborne, usually due to wind, soil disturbance and recreational activity.
83
Is there a vaccine available for cocci or valley fever?
no
84
What is cocci highly?
highly infective
85
What is there low of in cocci or valley fever?
low pathogenicity and virulence
86
Is susceptibility to cocci universal?
yes
87
Who is more at risk than the general population for cocci?
older adults
88
Who is the population at risk for the more severe form?
1. Filipino ancestry
2. black race
3. hispanics
4. native Americans
89
Who else is at risk for cocci?
People who are immuno-compromised due to HIV, organ transplants, Hodgkin's disease, diabetes, or chronic corticosteroid therapy
90
Is pregnancy a significant risk for cocci?
yes
91
People who recover from cocci have what?
lifelong active immunity
92
Where is cocci an endemic?
southwestern US
93
What kind of human behavior puts people at risk for cocci?
People who work or play at stirring up the soil, as in construction, excavation, farming, gardening and driving ATVs are at increased risk for infection.
94
true or false; cocci is seasonal
true; most infections occur during hot dry weather following a rainy season
95
is it easy to intervene in cocci?
no; it is hard to intervene during the susceptible stage and early subclinical stages of the disease
96
Is there a vaccine or cure for cocci?
no
97
what is the transmission of cocci?
airborne
98
what is the public health approach to cocci?
awareness to promote earlier diagnosis
99
is there person to person or animal to person transmission in cocci?
no
100
What is the agent of malaria?
4 species of plasmodium parasite
101
How is malaria transmitted?
by the bite of an infected female anopheles mosquito
102
What are host factors that make someone more susceptible to malaria?
1. Genetic factors-SCT, thalassemias
| 2. Pregnancy
103
What is airport malaria?
malaria caused by infected mosquitoes that are transported by aircraft from a malaria-endemic country to a non-endemic country.
104
What type of pathogens are plasmodium parasite?
virulent pathogens
105
what do Public health strategies for Malaria in the US focus on?
1. Primary Prevention measures, such as prophylactic medications, mosquito repellent and bed nets.
2. late Secondary Prevention activities to detect malaria earlier through recognition of symptoms.
106
What are the highest risk US communities for malaria?
1st and second generation immigrants
107
What is the agent for rabies?
rabies virus
108
Rabies has the highest what?
Rabies has the highest case fatality rate of any known human infection
109
What are factors that make a host susceptible to rabies?
all humans
110
Who are the primary hosts of rabies?
mammals
111
What is the most common mode of rabies virus transmission?
is through the bite, scratch, and contact with the virus-containing saliva of an infected animal.
112
How can someone have a non-bite exposure?
are rare but possible through transfusions and scratches, abrasions, and mucous membrane contamination with saliva from rapid animals.
113
Is rabies considered contagious?
no
114
What are public health strategies to prevent rabies?
1. campaigns to increase pet vaccinations
2. teaching people, especially children how to avoid bites and as well as the importance to seeking immediate medical attention for any possible exposures.
115
What are 3 treatment options for rabies?
1. wound care
2. human rabies immune globulin
3. vaccine.
116
What does immune globulin provide for rabies?
passive immunity
117
What does the vaccine provide for rabies?
active immunity
118
What are the 3 ways to control infectious diseases?
1. isolation
2. quarantine
3. social distancing
119
What does isolation refer to?
separating a sick and infectious host from others for the estimated communicable stage
120
What stage does isolation apply to?
communicable stage
121
What does quarantine refer to?
Those not sick but who have been exposed and are possibly infected and contagious
122
What stage does quarantine apply to?
incubation stage
123
Can both isolation and quarantine be voluntary or enforced and both states and the federal government have the authority to legally enforce them?
yes
124
What is social distancing?
a category of population-based public health interventions which aims to increase the space between people and decrease the frequency of contact among people in order to diminish the risk of transmission.
125
What are examples of social distancing?
1. School and work closures
2. Travel restrictions and border control
3. Mass gathering restrictions
126
What does social distancing ultimately do?
controls behavior of both potentially contagious and susceptible hosts?
127
what is the reduction to zero (or a very low defined target rate) of new cases in a defined geographical area?
elimination
128
What is the irreversible termination of all transmission of infection by extermination of the infectious agents worldwide?
eradication
129
What is the only disease to ever be fully eradicated in the US?
smallpox
130
What is the agent of polio?
poliovirus
131
Has polio been eradicated?
no, only eliminated in the Western Hemisphere and in Europe.
132
What is polio?
a highly infective virus which invades the nervous system potentially causing paralysis and death.
133
How is polio transmitted?
primarily through the oral-fecal route and sometimes through contact with saliva.
134
Can people have long term complications from polio?
Children under 5 are most at risk for paralysis and death.
135
Where is polio an endemic?
Afghanistan, Nigeria and Pakistan
136
What is the agent of Dracunculiasis or guinea worm disease?
Dracunculus medinensis (parasite)
137
How is guinea worm disease transmitted?
Indirect-contaminated water
138
is there a cure for guinea worm disease?
no
139
Has guinea worm disease been eliminated?
yes
140
What is the public health strategy for eradicating GWD?
preventing transmission of the parasite by providing clean water to all communities in at risk countries.
141
In 2019, GWD was limited to what?
Angola Chad, and Southern Sudan
142
What is the agent of smallpox?
variola virus
143
Has smallpox been eradicated?
yes since 1979
144
How does smallpox present?
characteristic and disfiguring skin eruptions
145
Is the vaccine for smallpox avialable?
Vaccine no longer available to general public; gov’t maintains supply
146
Who is the host of smallpox?
humans
147
How is smallpox transmitted?>
direct via droplets
148
Where is smallpox now?
in laboratories
149
What are the 17 routine vaccines available?
```
Chickenpox (Varicella)
Diphtheria
Flu (Influenza)
Hepatitis A
Hepatitis B
Hib (Haemophilus influenzae type b)
HPV (Human Papillomavirus)
Measles
Meningococcal
Mumps
Pneumococcal
Polio (Poliomyelitis)
Rotavirus
Rubella (German Measles)
Shingles (Herpes Zoster)
Tetanus (Lockjaw)
Whooping Cough (Pertussis )
```
150
What are the 7 non-routine vaccines available?
```
Adenovirus
Anthrax
Cholera
Japanese Encephalitis (JE)
Rabies
Smallpox
Tuberculosis
Typhoid Fever
Yellow Fever
```
151
How does public health use some of the reports for disease?
```
Interrupts transmission
Location/treatment of contacts
Identifies outbreaks
Alerts providers
Monitors disease trends
Identifies high risk groups
Priorities in resource allocation
Policy and program development
```
152
Who mandates reporting of infectious diseases?
state
153
What is violation of reporting rules?
a class III misdemeanor and is subject to being reported to the facility's licensing agency or provider's state licensing board.
154
Where are notifiable or reportable diseases reported?
1. HCPs report to county health departments
2. County health departments report to AZDHS
3. AZDHS reports to CDC
155
Where can you find the notifiable disease lists on a national level?
from CDC website
156
Where can you find the notifiable disease lists on a state level?
Arizona Department of Health Services
