Chapter 14 Flashcards

Principles of Disease and Epidemiology

1
Q

Pathology

A

Scientific study of disease, concerning the cause of disease and the structural and functional changes brought about by disease and with their final effects on the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Etiology

A

The study of the cause of disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Pathogenesis

A

The manner in which disease develops

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Infection

A

The invasion or colonization of the body by pathogenic microorganisms pr the presence of a microorganism in part of the body where it is not normally found. It can exist in the absence of detectable disease; no symptoms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Disease

A

Occurs when an infection results in any change from a state of health. It’s an abnormal state. The body cannot perform all it’s normal functions. Part or all of the body is not properly adjusted.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Human Microbiome Project

A

Began in 2007 to analyze microbial communities called microbiomes that live on and in the body. With a goal of trying to determine the relationship between changes in human microbiome and human health and disease.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Normal microbiota

A

Normal flora; Microorganisms that establish more or less permanent residents (colonize) but do not produce disease under normal conditions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Transient microbiota

A

Microorganisms that may be present for several days, weeks, or months and then disappear. They are not found throughout the entire human body but are localized in certain regions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the factors that determine the distribution and composition of normal microbiota

A

Nutrients, physical and chemical factors, defenses of the host, and mechanical factors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How do nutrients affect normal microbiota and where do they come from

A

Microbes can colonize only those body sites that can supply the appropriate nutrients. These nutrients maybe derived from secretory and excretory products of cells, substances in body fluids, dead cells, and foods in the gastrointestinal tract.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the physical and chemical factors that affect the growth of microbes and result in normal microbiota

A

Temperature, pH, available oxygen and carbon dioxide, salinity, and sunlight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are mechanical forces that the human body uses against microbes

A

Mechanical forces such as chewing, the flow of saliva and digestive secretions, the flushing of urine during urination.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does the human body’s protect itself against microbes

A

The human body has a variety of molecules and activated cells that kill microbes, inhibit their growth, prevent their adhesion to host cell surfaces and neutralize toxins that microbes produce.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Microbial antagonism

A

Also known as competitive exclusion. A manner in which normal microbiota can benefit the host by preventing the overgrowth of harmful micro organisms, involving competition among microbes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does microbial antagonism protect the host against colonization by potentially pathogenic microbes

A

Normal microbiota compete with pathogenic microbes for nutrients and they produce substances harmful to the invading microbes and affect conditions such as pH and available oxygen.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the relationship between the normal micro biota and the host called and what does it mean

A

Symbiosis. At least one organism is dependent on the other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Commenalism

A

Symbiotic relationship in which one of the organisms benefits and the other is unaffected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Mutualism

A

A type of symbiosis that benefits both organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Parasitism

A

A type of symbiosis where one organism benefits by deriving nutrients at the expense of the other.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How can a mutualistic organism become harmful? What’s an example

A

As long as it remains in it’s normal environment it is not infectious. Once it gets access to bbn other body sites it can become infectious. Example: E. coli in the large intestine is normal, if it gets into the urinary tract it can become infectious

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Opportunistic pathogens

A

Microbes that do not ordinarily cause disease in their normal habitat in a healthy person but may do so in a different environment. Example: E. coli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Example of commensalism

A

Staphylococcus epidermidis on the skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Example of mutualism, how

A

E coli in the large intestine. They synthesize Vit K and some B vit that are absorbed into the bloodstream and used by cells in the body. In exchange the large intestine provides nutrients used by baceria that allows for their survival

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Other than competition among microbes, what is another factor in the cause of disease

A

Cooperation among microbes. Example: pathogens that cause periodontal disease and gingivitis have been found to have receptors, not for teeth, but for oral streptococci that colonize the teeth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Noninfectious diseases
Diseases that are not caused by microorganisms, such as inherited and degenerative diseases
26
Infectious diseases
Disease caused by microorganisms
27
Where is a key criterion in the validity of any scientific proof
That the experimental results be repeatable
28
In summary, what are Koch's postulates
1. The same pathogen must be present in every case of the disease 2. The pathogen must be isolated from the diseased host and grown in pure culture 3. The pathogen from the pure culture must cause a disease when it is inoculated into a healthy susceptible laboratory animal 4. The pathogen must be isolated from the inoculated animal and it must be shown to be the original organism
29
What are some exceptions to Koch's postulates
They are modified to establish etiologies of diseases caused by viruses and some bacteria which cannot be grown on artificial media
30
What are some diseases that cannot be verified by Koch's postulates
▪︎Tetanus have unequivocal signs and symptoms ▪︎Pneumonia and nephritis may be caused by a variety of microbes ▪︎Certain pathogens, such as HIV, cause disease in humans only ▪︎Some pathogens, such as S. pyrogenes, cause several different diseases
31
Symptoms
Subjective changes in body function such as pain and malaise
32
Signs
Objective changes that can be observed and measured such as swelling, fever, and paralysis
33
Syndrome
A specific group of symptoms and signs that accompany a particular disease
34
Communicable disease
Any disease that spreads from one host to another, either directly or in directly
35
Examples of communicable diseases
Chicken pox, measles, general herpes, typhoid fever, tuberculosis
36
Contagious diseases
Diseases that are easily spread from one person to another
37
Examples of contagious diseases
Chicken pox and measles
38
Non communicable disease
Diseases caused by microorganisms that normally inhabit the body and only occasionly produce disease, and is not spread from one person to another. Some only cause disease when they reside on the body and somehow get inside the body.
39
Incidence
The number of people in a population who develop a disease during a particular time period
40
Prevalence
The number of people in a population who develop a disease at a specified time regardless of when it 1st appeared. This includes both old and new cases.
41
What is a good indicator of the spread of disease
Incidence
42
Sporadic disease
A disease that occurs only occasion only
43
Endemic disease
A disease constantly present in a population
44
Epidemic disease
A disease acquired in a given area in a relatively short period
45
Pandemic
A disease occurring in the world wide
46
Acute disease
A disease that develops rapidly but lasts only a short period of time
47
Chronic disease
A disease that develop slowly and the body's reaction May be less severe but the disease is likely to continue to recur for long periods
48
Sub acute disease
A disease that it is intermediate between acute and chronic
49
Latent disease
A disease in which a causative agent remains inactive for a time but then becomes active and produces symptoms of the disease
50
Herd immunity
When many Immune people are present in a community
51
Local infection
An infection in which the invading micro organisms are limited to a relatively small area of the body
52
Example of local infection
Boils and abscesses
53
Systemic infection
An infection in which micro organisms or their products are spread throughout the body by the blood or d lymph
54
Example of systemic infection
Measles
55
Focal infection
A confined infection to specific areas of the body that results from a local infection that entered the blood or lymphatic vessel and spread to those parts of the body
56
Where do focal infections usually arise from
Teeth, tonsils, or sinuses
57
Sepsis
A toxic inflammatory condition arising from the spread of my grobes especially bacteria or their toxins from a focus of infection
58
Septicemia
Blood poisoning, A systemic infection arising from the multiplication of pathogens in the blood
59
Example of septicemia
Sepsis
60
Bacteremia
Presence of bacteria in the blood
61
Toxemia
Presence of toxins in the blood
62
Example of toxemia
Toxins from the infection ction tetanus
63
Viremia
Presence of viruses in blood
64
Primary infection
An acute infection that causes initial illness
65
Secondary infection
An infection caused by an opportunistic pathogen after the primary infection has weakened the body's defenses
66
Common secondary infections
Occur of the skin and respiratory tract
67
Which would be more dangerous, a primary infection or secondary infection of the skin or respiratory tract
Secondary infection
68
Subclinical infection
AKA Inapparent infection, one that does not cause any noticeable illness
69
Predisposing factor
A factor that affects the occurrence of disease and makes the body more susceptible to a disease and may alter the course of the disease
70
Examples of predisposing factors
Gender, genetic background, climate and weather, inadequate nutrition, fatigue, age, environment, habitats, lifestyle, occupation, pre existing illness, chemotherapy, emotional disturbances
71
Sequence of development of disease
1. Incubation period 2. Prodromal period 3. Period of illness 4. Period of decline 5. Period of convalescence
72
Incubation period
The interval between the initial infection and the 1st appearance of any signs or symptoms.
73
The time of incubation depends on what
Specific microorganism involved, its virulence, the number of infecting microorganisms and the resistance of the host
74
Prodromal period
A relatively short. That follows the period of incubation. It is characterized by early, mild symptoms of disease, such as general aches and malaise
75
Period of illness
The disease's most severe in this stage. The person exhibits overt signs and symptoms of disease such as fever, chills, muscle pain, sensitivity to light, soar throat, lymoh node enlargement, and gastrointestinal disturbances. The number of white blood cells may increase or decrease. The patients immune response and other r defense mechanisms overcome the pathogen and the period of illness ends. If the disease is not successfully overcome, the patient dies during this period.
76
Period of decline
During this time the signs and symptoms go away. It can take from less than 24 hours to several days. The patient is vulnerable to secondary infections.
77
Period of convalescence
The person regains strength and the body returns to its pre disease. Recovery has occurred.
78
During which development of disease period can one serve as a reservoir and spread infection to other people
Incubation, period of illness, and convalescence
79
Reservoir of infection
A source that can be either living or an inanimate object that provides a pathogen with adequate conditions for survival and multiplication and an opportunity for transmission
80
What are the different types of reservoirs
Human, animal, and non living
81
Human reservoir
Many people harbor pathogens and transmit them directly or indirectly to others. This can occur when people have signs and symptoms of disease or they can be carriers
82
When are people considered carriers of a disease
During the latent peroid, during incubation, or during the convalescent period.
83
Animal reservoirs
Both wild and domestic animals are living reservoirs that can carry microorganisms that can cause human disease
84
Zoonoses
Diseases that occur primarily in wild and domestic animals and can be transmitted to humans
85
Examples of zoonoses
Rabies and Lyme disease
86
How are zoonoses transmitted to humans
Direct contact with infected animals, By direct contact with domestic pet waste, By contamination of food and water, By air from contaminated hides, furs or feathers, By consuming infected animal products, By insect vectors
87
2 major Nonliving reservoirs
The 2 major non living reservoirs of infectious disease or soil and water
88
What microbes does soil harbor
Fungi and bacteria
89
How is water usually contaminated
By the faces of humans and other animals, It's fully responsible for gastrointestinal disease
90
What are other non living reservoirs
Improperly prepared are stored food
91
What are the different ways disease can be transmitted
Contact transmission, Vehicle transmission, Vectors
92
Contact transmission
The spread of an agent of disease by direct contact, indirect contact, droplet transmission
93
Direct contact
Person to person transmission by physical contact between its source and a susceptible host
94
What diseases can be transmitted through direct contact
Viral respiratory tract diseases, staphylococcal infections, hepatitis A, measles, scarlet fever, and STD's. Pathogens from animals to humans can occur by direct contact as well.
95
Indirect contact transmission
Occurs when the agent of disease is transmitted from its reservoir to a susceptible hosts by means of a nonliving object
96
Term for a nonliving object involved in the spread of infection
Formite; tissues, eating utensils, towels, money contaminated syringes
97
Droplet transmission
Microbes that are spread in droplet nuclei that trouble only short distances. These droplets or discharge into the air by coughing, sneezing, laughing, or talking and travel less than one meter from reservoir to the host.
98
Vehicle transmission
The transmission of a disease by a medium such as water, food, air, body fluids, drugs, intravenous fluids.
99
Most important group of disease vectors
Arthropods are the most important group of disease vectors, animals that carry pathogens from one host to another
100
What are the to general method arthropods transmit disease
Mechanical and biological transmission
101
What is mechanical transmission
It is the passive transport of pathogens on the insects feet or other body parts
102
Biochemical transmission
An active process of transmission in which the arthropod bites an infected person or animal and ingest some of the infected blood. The pathogen reproduces inside the vector and this increases the number of pathogens which increases the possibility that they will transmit to another host.
103
Nosocomial infection
An infection that is acquired as a result of a hospital stay or acquired in another healthcare facility
104
Which facilities cause health care associated infections
Same day surgical centers, ambulatory outpatient healthcare clinics, nursing homes, rehab homes,1 and home health care environments
105
What are the 3 factors that are involved in a nosocomial infection
1. Microorganisms in the hospital environment 2. The compromised status of the host 3. The chain of transmission in the hospital
106
Compromised host
One whose resistance to infection is impaired by disease, therapy, or burns
107
What are the 2 principal conditions that can compromise a host
Broken skin or mucous membrane and a suppressed immune system
108
What is the 1st line of defense of a host
The skin
109
What can break the 1st line of defense and make a person more susceptible to disease
Burns, surgical wounds, trauma, injections, invasive diagnostic procedures, ventilators, intravenous therapy, urinary catheter
110
Other than the 1st line of defense what is another thing that can increase a hosts susceptibility to infection
Things that can alter breathing and contribute to pneumonia
111
Principal routes of transmission in the hospital
1. Direct contact transmission from hospital staff to patient and from patient to patient 2. Indirect contact transmission through formites and the hospital's ventilation system
112
What is the single most important means of preventing the spread of infection
Handwashing
113
Emerging infectious diseases
Diseases that are new or changing, showing an increase in incidence in the recent past, or potential to increase in the near future
114
What percent of emerging infections are zoonotic
75%
115
What factors contribute to the emergence of new infectious diseases
1. New strains 2. New serovar: evolution 3. Unwarranted use of antibiotics and pesticides 4. Global warming/changes in weather patterns 5. Spread of disease to new geographic areas by modern transportation 6. Unrecognized infections appearing in individuals were an environment is undergoing ecological changes 7. Animal control or the lack of 8. Failures and public health measures such as lack of vaccinations
116
How did the CDC and NIH and the WHO develop plans to address issues related to emerging infectious diseases
1. Detect, investigate and monitor infectious pathogens 2. Expand basic and applied research on ecological, environmental factors, microbial changes, adaptations, host interactions that influence EIDs 3. Enhance communication of public health information and prompt implementation of prevention strategies 4. Establish plans to monitor and control EIDs worldwide
117
Epidemiology
The science that studies when and where diseases occur and how they are transmitted in populations
118
What is an epiemiologists job
To study the etiology of disease and identify other possibly important factors in patterns concerning the people affected, how to control it, how effectively is it being controlled, provide data to help evaluate and plan the overall health care for a community
119
What are the 3 basic types of an investigation when analyzing occurrence of disease
1. Descriptive epidemiology 2. Analytical epidemiology 3. Experimental epidemiology
120
Descriptive epidemiology
Involves the collection of data that describes how the disease developed. This includes information about those that were affected, and the place and period of time it occurred.
121
Descriptive epidemiology
Involves the collection of data that describes how the disease developed. This includes information about those that were affected, and the place and period of time it occurred.
122
Analytical epidemiology
evaluates a disease to determine why it occurred.
123
What are the 2 types of analytical epidemiology
The case control method and the cohort method
124
What is the case control method
With the case control method, epidemiologist compare a group of people with the disease and a group of people free from the disease. These groups are similar in age, sex, socioeconomic status, and location. They then look at factors that may have contributed to the incidence of the disease. These might include genetic, environmental, and nutritional factors.
125
What is the cohort method
With the cohort method, two populations are examined. They include one that has had contact with the agent and another that has not. 
126
Experimenter epidemiology
an experiment that is done in regard to a specific disease. A hypothesis is made, and an experiment is done with a group of people. They might possibly test a drug to measure its effectiveness. 
127
What is case reporting
A procedure that requires health care workers to report specified diseases to local, state, and national health officials
128
CDC
The centers for disease control and prevention is a branch of the United States public health service and a central source of epidemiological information
129
Morbidity
The incidence if a specific notifiable disease
130
Mortality
Number of deaths from a specific specific disease
131
Isolation
the act of separating a sick individual with a contagious disease from healthy individuals without that contagious disease
132
Quarantine
A period of isolation decreed to control the spread of infectious disease. These people may have been exposed to a disease and do not know it, or they may have the disease but do not show symptoms.