Infection, Infectious Diseases, and Epidemiology Flashcards
1
Q
Symbiosis means
A
To live together
2
Q
We have symbiotic relationships with countless
A
Microorganism
3
Q
Resident Microbiota
A
Part of microbiota for life
4
Q
Transient Microbiota
A
Remain in body for hours; but can not persist in the body
5
Q
Why cant Transient Microbiota persist in the body
A
Competition from other microbiota
Elimination by the bodys defense cells
6
Q
What is an example of the bodies defense system
A
WBC
Chemical or physical change in the body
7
Q
Axenic environment
A
Development in womb, free of microorgansim
8
Q
When do microbiota begin to develop
A
During birthing process
9
Q
Much of ones resident microbiota established during the
A
first month of life
10
Q
Opportunistic Pathogens
A
Normal microbiota that cause diseases under certain circumstances
11
Q
Opportunistic Pathogens
A
Normal microbiota that cause disease under certain circumstances
12
Q
Condition that provide opportunities for pathogens
A
- Introduction of normal microbiota into unusual site in body
- Immune suppression
- Changes in the normal microbiota
13
Q
Changes in relative abundance may allow opportunity for a member
A
to thrive and causes disease
14
Q
Most _________ cannot survive long outside of their host
A
Pathogens
15
Q
Reservoirs of Infection
A
Sites where pathogens are maintained as a source of infection
16
Q
Three types of reservoirs
A
- Animal reservoirs
- Human carries
- Nonliving reservoir
17
Q
Zoonoses
A
Diseases naturally spread from animals host to humans
18
Q
Acquire zoonoses through various routes
A
- Direct contact with animals or its waste
- Eating animals
- Bloodsucking arthropods
19
Q
Humans are usually dead-end host to
A
Zoonotic
20
Q
Infected individuals who are asymptomatic but
A
Infective to other
21
Q
Some individuals eventually develop illness while others never get sick while
A
Healthy carriers may have defensive systems that protect them
22
Q
_______________ can be reservoirs of infection
A
Soil water, and food
23
Q
Presence of microorganisms often due to contamination by ______________.
A
Feces or urine
24
Q
Exposure to Microbes
A
Contamination and infection
25
Contamination
The mere presence of microbes in or on the body
26
Infection
When organism evades body's external defenses, multiplies and becomes established in the body
27
Portals of Entry
Sites through which pathogens enter the body
28
Four major pathways (portals of entry)
Skin
Mucous Membrane
Placenta
Parenteral route
29
Skin
Outer layer of dead skin cells acts as a barrier to pathogens
30
Some pathogens can enter through
Opening or cuts
31
Others enter by burrowing into or
Digesting out layer of skin
32
Mucous membranes
Line the body cavities that are open to the environment
33
Provide a moist, warm environment hospitable to pathogens
Mucous membranes
34
_______________ is the most common site of entry
Respiratory tract
35
respiratory tract is the common site of entry entry is though the
Nose,
Mouth
Eye
36
______________ may be route of entry but must survie the _____pH of the stomach
Gastrointestinal tract
| Acidic
37
Placenta
Ephemeral organ, delivers nutrients to fetus, carries wastes away
38
Typically forms effective barrier to pathogens
Placenta
39
Pathogens may cross the placenta and infect the _____.
Fetus
40
Spontaneous abortion, birth defects, premature death is caused by
Pathogens crossing the placenta and infect the fetus
41
Parenteral route
Not a true portal of entry
42
Parenteral route; not a true portal of entry....
means by which the portal of entry can be circumvented
43
Pathogens deposited directly into tissues beneath the
Skin or mucous membranes
44
The role of adhesion in infection
Process by which microorganisms attach themselves to cells
45
Uses adhesion factors
specialized structures
| attachment proteins
46
Specialized structures
Adhesion disks, suckers, hooks
47
Attachment proteins
Ligands (Adhesions)
48
Binding of ligand and receptor may
determine specificty
49
Attachment proteins help in
Adhesion
50
Found on viruses and many bacteria
Attachment proteins
51
Viral or bacterial ligands bind host cell receptors
Interaction can determine host cells specificity
52
______________ a ligand or its receptor can prevent infection
Changing/blocking
53
Inability to make attachment proteins or adhesins renders microorganisms
avirulent
54
other bacterial pathogens attach to each other to form a
Biofilm
55
Is the invasion of the host by a pathogen
Infection
56
results if the invading pathogen alters normal body functions
Disease
57
Disease is also referred to as
Morbidity
58
Symptoms, signs, and syndromes
Manifestation of disease
59
Subjective characteristics of disease felt only by the patient
Symptoms
60
Objective manifestation of disease observed or measured by others
Signs
61
Symptoms and signs that characterize a disease or abnormal condition
Syndromes
62
Infections lack symptoms but may still have signs of infection
Asymptomatic, or subclinical
63
Causation of disease
Etiology
64
Disease caused by infections of pathogenic microorganisms
Germ theory of disease
65
Robert Koch developed a set of postulates one must satisfy to prove a
Particular pathogen causes a particular disease
66
Difficulties in satisfying Koch's postulates diseases can be caused by
more then one pathogen
67
Difficulties in satisfying Koch's postulates pathogens that are ignored
as potential causes of disease
68
Ability of a microorganism to cause disease
Pathogenicity
69
Degree of pathogenicity (Ease of infection)
Virulence
70
Virulence factors (Contribute to virulence)
```
Adhesion factors
Biofilms
Extracellular enzymes
toxins
Antiphagocytic factor
```
71
___________ secreted by the pathogen
Extracellular enzymes
72
- Dissolve structural chemicals in the body
| - Help pathogen maintain infection, invade, and avoid body defenses
Extracellular enzymes
73
Hyaluronidase and Collagenase
-Invasive bacteria reach epithelial surface
-Bacteria produce hyaluronidase and collagenase
-Bacteria invade deeper tissues
(Extracellular enzymes)
74
Coagulase and Kinase
- Bacteria produce coagulase
- Clot forms
- Bacteria later produce kinase, dissolving clot and release bacteria
75
Chemicals that harm tissues or trigger host immune responses that cause damage
Toxins
76
refers to toxins in the bloodstream that are carried beyond the site of infection
Toxemia
77
Cytotoxins, neurotoxins, and enterotoxins
Exotoxins
78
Lipid A
Endotoxins
79
Composed of chemicals not recognized as foreign
Bacterial capsule
80
Slippery; difficult for phagocytes to engulf bacteria- Invade phagocytes
Bacteria capsule
81
Prevent fusion of lysosome and phagocytic vesicles
| -Leukocidins directly destroy phagocytic white blood cells
Antiphagocytic chemicals
82
Bacteria secret exotoxins, in this case a cytotoxins
| -Cytotoxin kills host's cells
Exotoxin (Toxins)
83
Dead gram-negative bacter release endotoxin (lipid A) which induces effects such as fever, inflammation, diarrhea, shock, and blood coagulation
Endotoxins
84
The _________ occurs following infection
Disease process
85
Many infectious diseases have ___ stages following infection
5
86
What are the five stages following infection
- Incubation Period
- Prodromal period
- Illness
- Decline
- Convalescence
87
Incubation period
No signs or symptoms
88
Prodromal Period
Vague; general symptoms
89
Illness
Most severe signs and symptoms
90
Decline
Declining signs and symptoms
91
Convalescence
No signs or symptoms
92
Pathogens leave host through portals of
Exits
93
Many portals of exit are the
Same as portals of entry
94
Pathogens often leave hots in materials the body
Secretes or excretes
95
Is from a reservoir or a portal of exit to another's portal of entry
Transmission
96
3 groups of transmission
Contact Transmission
Vehicle Transmission
Vector Transmission
97
Direct, indirect or droplet
Contact Transmission
98
Airborne, waterborne or foodborne
Vehicle Transmission
99
Biological or mechanical
Vector Transmission
100
Diseases can be classified in number of ways
- The body system they affect
- Taxonomic categories
- Their longevity and severity
- How they spread to host
- The effects they have on populations (rather then on individuals)
101
Develops rapidly, lasts a short time
Acute disease
102
Chronic disease
Develops slowly, continual or recurrent
103
in-between chronic and acute
Subacute disease
104
Pathogen remains un-active for long duration
Latent disease
105
Disease is spread by another infected host directly or indirectly
Communicable
106
Communicable diseases that spread easily
Contagious
107
A disease that does not come from a host
nonCommunicable
108
Study of where and when diseases occur, and how they are transmitted
Epidemiology
109
Occurrence of diseases tracked using 2 measures
Incidence
| Prevalence
110
Number of new cases of a disease in a given area during a given period of time
Incidence
111
Number of total cases of a disease in a given area during a given period of time
Prevalence
112
Occurrence also evaluated in terms of
Frequency and geographic distribution
113
Infection aquired at a health care facility
Nosocomial infection
114
Types of nosocomial infections
Exogenous
| Endogenous
115
Pathogen acquired from the health care setting
Exogenous
116
Pathogen arises from normal microbiota due to factors within the health care setting
Endogenous
117
Results from modern medical procedures
Latrogenic
118
Control of nosocomial infections
- Precautions designed to reduce factors that result in disease
- Hand washing is the most effective way to reduce nosocomial infections
