Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

From Flashcardlet > Micro/Immuno URT > Flashcards

Micro/Immuno URT Flashcards

1
Q

What is the upper respiratory tract?

A 
Nose
Nasal cavity
Nasopharynx
Larynx
Sinuses
Eustachian tube
Ducts, glands
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How do pathogens enter the URT?

A

Inhalation or fomites

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

What are fomites?

A

Any substance capable of carrying infectious organisms, hence transferring them from one individual to another

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

What are some examples of fomites?

A

Skin cells
Hair
Clothing
Bedding

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

Why do URT infections have a risk of becoming LRT infections?

A

RT is a continuum

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

What does the focus of a pathogen’s site of infection relate to?

A

Can infect many sites, but mostly relates to receptors on the cells and the distance needed to be travelled

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

Do all pathogens that infect URT try to spread to LRT?

A

No, some pathogens will stay on the epithelium or submucosal layers of the URT

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

What are some examples of defenses in the URT?

A
  • Nose hairs
  • Mucous
  • Cilia
  • Regional lymphoid tissues (tonsils)
  • Normal flora
  • Lysozyme in saliva
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does the normal flora act as a defense in the URT?

A

Can produce bacteriocidins and also prevent adhesion by pathogens

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

What cells does lysozyme typically affect?

A

Gram positive, some gram negative

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

What is pharyngitis?

A

Sore throat

Inflammation of mucous membranes in the throat

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

What is laryngitis?

A

Inflammation of mucous membranes in the larynx

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

What is viral rhinitis?

A

Viral infection and inflammation of the URT

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

What is the etiology of the common cold?

A

Over 275 known viruses

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

Where do the viruses causing the common cold bind?

A

All bind to epithelial cells, often ciliated cells, or the URT

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

What mechanism do the viruses of the common cold induce?

A

Endocytosis

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

What are the most common type of viruses that cause the common cold?

A

Rhinoviruses

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

What is another name for the common cold?

A

Viral rhinitis

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

Are rhinoviruses ss/ds/DNA/RNA?

A

ssRNA

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

Do rhinoviruses have an envelop or capsule?

A

Non enveloped

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

What shape are rhinoviruses?

A

Spherical

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

What does the small diameter of viruses help them with?

A

Able to spread very quickly

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

Are coronaviruses ss/ds/DNA/RNA?

A

ssRNA

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

Do coronaviruses have an envelop or capsule?

A

Enveloped

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What shape are coronaviruses?

A

Spherical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are five viruses that cause the common cold?

A 
Rhinovirus
Coronavirus
Coxsackie virus
Adenovirus
Parainfluenza virus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the reservoir for the common cold?

A

Humans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the transmission method for the common cold?

A

50% inhalation of respiratory droplets

50% fomites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the incubation period for the common cold?

A

2-5 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How does a virus causing the common cold get into the URT and cause disease?

A
  • Binds to receptors on epithelial cells
  • Induces endocytosis
  • Uncoats the capsid of the cell
  • Replicates nucleic acid and proteins
  • Assembly
  • Cell damage and/or lysis
  • Release of cytokines and inflammatory mediators
  • Spread to neighboring cells
  • Inflammation along URT
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Where is the infection of the common cold limited to?

A

Epithelium and sbmucosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the pathology of the common cold?

A

Cell lysis of epithelial cells and desquamification causes edema of mucosal surface and other inflammatory symptoms (ex. increased mucous), leading to congestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How long does the common cold usually last?

A

4-7 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

How does the body get over the common cold?

A

Self limiting - you get better on your own from antibody and cytotoxic T cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the period of contagion of the common cold?

A

1-2 days before signs and symptoms, persists throughout the period of illness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

If we develop immunity to a cold, why do we get colds yearly?

A

We usually develop immunity to the virus that caused that particular cold, but 1000s of viruses can cause the common cold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

How does the body recover from desquamification?

A

Regeneration of epithelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What are the five common signs and symptoms of the common cold?

A
  • Irritation of URT
  • Increased nasal discharge and congestion
  • Swelling and erythema of mucosa
  • Diminished sense of smell
  • Sneezing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What are some symptoms that may or may not present with the common cold?

A 
Watery eyes
Sore throat
Headache
Mild cough
Hoarseness
Aches
Fever - very rare
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

How do we diagnose the common cold?

A

Signs and symptoms - virus is never identified

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Why don’t we identify the virus causing the common cold?

A

Cold is not serious, it is costly, and there are 1000s of viruses that could cause the cold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is the treatment for the common cold?

A

Cold remedies - no vaccinations because there are too many antigenic variants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

What are some methods of prevention of the common cold?

A

Wash hands, don’t share tissues with individuals with colds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is epidemiology?

A

study of the patterns, causes, and effects of health and disease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What is the epidemiology of the common cold?

A

Temperate latitudes

Younger children ages 2-4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What happens to the instances of colds as we age?

A

We get less colds as we grow older - maybe because we have developed more immunity against the common viruses causing colds, and our immune systems are overall stronger as we age

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What is viral pharyngitis and tonsillitis?

A

Infection and inflammation of mucous membranes of the throat and tonsil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What types of viruses cause pharyngitis?

A
  • Adenovirus
  • Rhinovirus
  • Coronavirus
  • Epstein-Barr virus
  • Herpes simplex virus
  • Coxsackie A virus
  • Echovirus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

Are adenoviruses ss/ds/DNA/RNA?

A

ssDNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

Are adenoviruses enveloped?

A

Non enveloped

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What shape are adenoviruses?

A

Spherical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Do we identify what virus causes a sore throat?

A

Usually do not identify in mild cases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What is the reservoir for pharyngitis?

A

Humans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What is the transmission methods for pharyngitis?

A

Droplets
Fomites
Movement down to throat from nasal passages
Saliva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What is the pathogenesis of pharyngitis?

A
  • Virus gets to mucosal surface of pharynx and binds to receptors
  • Induces endocytosis and invades epithelial cells
  • Virus uncoated
  • Virus replicates nucleic acids and proteins
  • Cell damage and lysis
  • Release of cytokines and inflammatory mediators
  • Inflammation of pharynx (sore throat)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What is the incubation period of pharyngitis?

A

3-10 days depending on the virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

How does the body recover from pharyngitis?

A

Usually self limiting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

What is the period of illness for pharyngitis?

A

2-8 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What are the signs and symptoms of pharyngitis?

A
  • Inflammation fo pharynx
  • Pain
  • Erythema
  • Fever - if bacterial
  • Usually no discharge
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

If pharyngitis is really painful and presents with a fever, is it probably viral or bacterial?

A

Bacterial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

How do we diagnose pharyngitis?

A

Mostly by signs and symptoms - usually do not identify virus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

What is the treatment of pharyngitis?

A

Treatment of symptoms, self limiting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

What is the epidemiology of pharyngitis?

A

Temperate latitudes

About 2 million doctor visits a year

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

What virus causes adenoviral pharyngitis?

A

Adenovirus strains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

What is another name for adenoviral pharyngitis?

A

Pharyngoconjunctival fever

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

What is the reservoir for adenoviral pharyngitis?

A

Humans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

What is the transmission method for adenoviral pharyngitis?

A

respiratory droplets
Fomites
Fecal material in swimming pools

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

What is the incubation period for adenoviral pharyngitis?

A

5-12 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

What is the period of contagion for adenoviral pharyngitis?

A

1-4 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

Where does adenoviral pharyngitis infect the body?

A

Pharynx and conjunctiva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

What is the pathogenesis of adenoviral pharyngitis?

A
  • Virus binds to receptors on pharynx and conjunctiva
  • Induces endocytosis and invades cells
  • Uncoating
  • Viral replication of nucleic acid and proteins
  • Cell damage and cell lysis
  • Spread
  • Release of cytokines and inflammatory mediators
  • Inflammation of throat and conjunctiva (conjunctivitis)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

What are the signs and symptoms of adenoviral pharyngitis?

A
  • Severe pharyngitis
  • Painful sore throat
  • Usually high fever lasting several days
  • Moderate to severe cough
  • Swelling of cervical lymph nodes
  • White exudate/pus over tonsils and pharynx
  • Conjunctivitis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

What substances are released with adenoviral pharyngitis that cause fever?

A

Pyrogens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

What is seen in adenoviral pharyngitis that is not seen in mild forms of sore throat?

A

Fever and exudate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

How do we diagnose adenoviral pharyngitis?

A

Signs and symptoms
History
Immunodiagnostics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

What kind of immunodiagnostics do we use to diagnose adenoviral pharyngitis?

A

Fluorescent antibodies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

What is the treatment for adenoviral pharyngitis?

A

Treat symptoms

Vaccine for military was previously available

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

What is the epidemiology of adenoviral pharyngitis?

A

Temperate latitudes
Common among children in summer camps - swimming pools
Young adults

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

What pathogen would cause a serious infection of the throat?

A

Bacterial

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

Where do bacterial infections of the pharynx occur?

A

Mucosal surface - bacterial usually does not invade the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

What virus causes strep pharyngitis?

A

Streptococcous pyogenes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

What kind of gram cell is S pyogenes?

A

Gram positive coccus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

What kind of lance field group is S pyogenes?

A

Lancefield GroupA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

What kind of hemolysis does S pyogenes cause?

A

Beta hemolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

What does streptococcus pyogenes look like?

A

Round and in chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

How many types of antigenic strains of S pyogenes have been identified?

A

Over 50 strains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

What characteristics do S. pyogenes have that prevent phagocytosis?

A

Antiphagocytic M protein

Capsules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

What kind of toxins does S. pyogenes make?

A

Streptolysins
Erythrogenic toxin
Streptokinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

What do streptolysins do?

A

Kill erythrocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

What is the reservoir for S. pyogenes?

A

Human

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

What are the transmission methods for S. pyogenes?

A

Pharynx by respiratory droplets
Foodborne
Saliva - children’s toys/kissing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

What is the incubation period of strep pharyngitis?

A

2-5 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

What is the pathogenesis of strep pharyngitis?

A
  • Adheres with adhesins to pharyngeal epithelial cells via receptors
  • Replicates on surface of pharynx; does not usually invade, but occasionally gets access to circulation and can move to other body sites
  • Avoids phagocytosis by M proteins or capsules
  • Secretes enzymes
  • Causes tissue damage and cell lysis
  • Induces release of cytokines and inflammatory mediators
  • Causes inflammation of pharynx
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
94
Q

What does streptokinase do?

A

Lyse fibrin clots

95
Q

Where does S. pyogenes replicate?

A

Does not need to be inside of cell, can replicate on cell surface

96
Q

Which strains of S. pyogenes are not virulent?

A

Strains that lack M protein or capsules because they cannot evade phagocytosis

97
Q

What does the pathology of strep pharyngitis come from?

A

Partially from the replication of S. pyogenes on the cell surface, but mostly from enzymes that the pathogen secretes that causes cell and tissue damages

98
Q

What is the duration of strep pharyngitis?

A

Even without antibiotics, usually only one week

Younger children may have it for several weeks

99
Q

What does strep throat lead to if not treated?

A

Scarlet fever
Rheumatic fever
Glomerulonephritis

100
Q

What are the signs and symptoms of strep throat?

A
  • Severe pharyngitis
  • Severe pain, especially during swallowing
  • Erythema (reddening) in throat with patches of white exudate; tiny hemorrhages on pharynx and tonsils
  • in adults, usually high fever; lower in children
  • headache
  • enlarged cervical lymph nodes
  • abscess formation on tonsils
    loss of appetite
  • cough, runny nose, red, tearing eyes
101
Q

Are the signs and symptoms of strep throat always the same?

A

No they can vary from mild, similar to a cold, to severe

102
Q

How do we diagnose strep pharyngitis?

A

Signs and symptoms
Beta hemolysis on a blood agar plate
Agglutination tests

103
Q

What is gamma hemolysis?

A

No enzymes present to cause hemolysis of RBCs

104
Q

What is beta hemolysis?

A

Many effective enzymes present to cause complete hemolysis in 24 hours

105
Q

What is alpha hemolysis?

A

Some enzymes that may not be as effective in hemolysis in 24 hours

106
Q

What is the treatment for strep throat?

A

Treat signs and symptoms

Antibiotics like penicillin or erythromycin

107
Q

Why is it important to identify and treat S. pyogenes?

A

Because we want to prevent the secondary diseases that are more severe that can arise from strep throat

108
Q

What is the epidemiology of strep throat?

A

Common age 5-15
15% of all sore throats
Several million cases a year in U.S.

109
Q

Which kind of virus has not developed resistance to penicillin?

A

Streptococcus - still as vulnerable as it was 50 years ago

110
Q

What kind of specificity does scarlet fever have?

A

Strain specific

111
Q

What kind of specificity does rheumatic fever have?

A

Strain and host specific

112
Q

What kind of specificity does glomerulonephritis have?

A

Strain and host specific

113
Q

When do secondary complications of strep throat usually occur?

A

Can occur about 3 weeks after a primary infection

114
Q

What are secondary complications of strep throat resulting from?

A

Usually due to several different S. pyogenes strains acting at once

115
Q

What causes scarlet fever?

A

Certain strains of S. pyogenes that produce erythrogenic toxins

116
Q

What are some examples of erythrogenic toxins?

A

Pyrogenic toxins A, B, C

117
Q

What is the reservoir for scarlet fever?

A

Human

118
Q

What is the transmission methods for scarlet fever?

A

Respiratory droplets

Fomites

119
Q

What is the pathogenesis for scarlet fever?

A

Proceeded by a/symptomatic strep throat with erythrogenic strains

  • Toxins enter circulation
  • Toxins localize in skin capillaries
  • Damage to blood capillaries under skin and tongue
120
Q

What does damage to blood capillaries under the skin present with?

A

Hemorrhage and rash

121
Q

What does damage to blood capillaries under the tongue present with?

A

Whitish coating

122
Q

What are the signs and symptoms of scarlet fever?

A
  • Strep thorat S&S
  • 2-14 days later present with fever of at least 101
  • Headache
  • Sore throat
  • 1-2 days later, red punctuate rash on upper torso and face
  • Punctuate rash then spreads to rest of body except palms and soles
  • Rash fades
  • Extensive desquamification for 2-3 weeks
  • Tongue is white at first, then spotted and strawberry like with prominent papillae, then red and enlarged
  • Enlarged cervical lymph nodes
123
Q

Where does a rash from scarlet fever present?

A

Starts on upper torso and face

Moves to everywhere except palms of hands and soles of feet

124
Q

What does the tongue look like in scarlet fever?

A

First white
Spotted then strawberry like with prominent papillae
Red and enlarged

125
Q

When does recovery of scarlet fever typically begin?

A

Once antibodies start to be produced, recovery begins - usually no lasting problems persist

126
Q

How do we diagnose scarlet fever?

A

Signs and symptoms
Identify S. pyogenes by culture
Identify toxin immunologically

127
Q

What is the treatment of scarlet fever?

A

Antibiotics - may not help because it will not affect the toxin symptoms

128
Q

What is disqualification?

A

Peeling of skin, or shedding of the outermost layer of a tissue

129
Q

What is the epidemiology of scarlet fever?

A

Most common ages 5-15

More common in untreated cases of strep throat

130
Q

What causes glomerulonephritis?

A

Certain strains of S. pyogenes that are prone to forming immune complexes

131
Q

What is the reservoir for glomerulonephritis?

A

Human

132
Q

What are the transmission methods of glomerulonephritis?

A

Respiratory droplets
Fomites
Sometimes strep skin infections

133
Q

What is the pathogenesis of glomerulonephritis?

A

Approx 3 weeks after primary infection with certain staring of S. pyogenes

  • Immune complex formation between antibody and antigen
  • Complexes deposit in glomerulus and get trapped
  • Inflammation in nephron of kidney
  • Damage to kidney depending on how many complexes are formed
134
Q

How are the immune complexes in glomerulonephritis eventually removed?

A

Removed by phagocytes, which takes time and can cause inflammatory damage in the mean time

135
Q

Does glomerulonephritis cause kidney damage?

A

Usually does not cause permanent kidney damage and results in complete recovery

136
Q

When does kidney failure result in glomerulonephritis?

A

Rarely, due to massive immune complex deposition and inflammatory damage, or repeated occurrences

137
Q

What is the host specific aspect of glomerulonephritis?

A

How many complexes are formed in the host and whether the phagocytes of the host can remove them

138
Q

What are the signs and symptoms of glomerulonephritis?

A
  • Abrupt fever
  • Hypertension
  • Hematuria (dark urine due to erythrocytes)
  • Proteinuria
  • Edema in nephron; Periorbital edema (puffiness of face or eyelids
  • Low serum complement levels
  • Sometimes more generalized edema, malaise, anorexia, vomitting
139
Q

When do signs and symptoms of glomerulonephritis present?

A

1-3 weeks after initial strep throat infection

3-6 weeks after skin infection

140
Q

How do we diagnose glomerulonephritis?

A

Signs and symptoms
Urinalysis
Anti-Dnase test

141
Q

What is an anti-Dnase test?

A

Used to identify antibody to a substance made by group A strep (Dnase) in blood

142
Q

Is an anti-Dnase test direct or indirect?

A

Indirect

143
Q

What is the treatment of glomerulonephritis?

A

Treat symptoms of strep throat

Antibiotics to kill any remaining S. pyogenes

144
Q

What is the epidemiology of glomerulonephritis?

A

Most common in ages 5-15

About 0.1% secondary strep infections in developed world

145
Q

What is the cause of rheumatic fever?

A

Certain strains of S. pyogenes

146
Q

What is the reservoir for rheumatic fever?

A

Human

147
Q

What is the transmission methods for rheumatic fever?

A

Respiratory droplets
Fomites
Sometimes strep skin infections

148
Q

What is the pathogenesis of rheumatic fever?

A

Characterized by inflammation of various joints, skin, heart, and sometimes brain

149
Q

What does the damage to the heart in rheumatic fever involve?

A

Damage to heart valves resulting in scarring

150
Q

What does repeated episodes of rheumatic fever result in?

A

Can result in heart failure and death

151
Q

When does rheumatic fever present?

A

About 3 weeks after primary strep throat or scarlet fever

152
Q

What component of rheumatic fever is host specific?

A

Autoimmune component

153
Q

What is the autoimmune component to rheumatic fever?

A

Host antigens on heart valves are very similar to the antigens or strep - the immune response can’t distinguish between self and non self (antigen mimicry)

154
Q

What are antibodies produced against in rheumatic fever?

A

M protein

155
Q

What are the signs and symptoms of rheumatic fever?

A
  • Fever
  • Malaise
  • Polyarthritis (knees, elbows, ankles, wrists mailnly) and joint swelling
  • Signs of cardiac problems (chest pain, shortness of breath)
  • Nose bleeds
  • Skin rash/eruptions on trunk and upper part of arms and legs
156
Q

What does the rash look like in rheumatic fever?

A

Ring shaped or snake like

157
Q

How do we diagnose rheumatic fever?

A

Signs and symptoms
History - strep infection?
Electrocardiogram
Echocardiography

158
Q

What is the treatment for rheumatic fever?

A

Anti-inflammatory medications and antibiotics

159
Q

What is the epidemiology of rheumatic fever?

A

2% of strep throat cases

75 reported cases each year

160
Q

What is the etiology of otitis media?

A

Different viruses and bacteria
Virus - Mumps, RSV
Bacteria - Strep pneumoniae, Haemophilus influenza, Mycoplasma pneumoniae, S pyogenes

161
Q

Which pathogens are secondary invaders in otitis media?

A

Bacteria - viruses are usually primary infectors

162
Q

What is the reservoir of otitis media?

A

Humans

163
Q

What is the transmission method of otitis media?

A

Usually spread in secretions
Sometimes in contaminated water
Trauma to eardrum

164
Q

What is the pathogenesis of otitis media?

A

First infection of nose or throat
Spreads through eustachian tube to middle ear
- Induce inflammation and edema

165
Q

How do viruses travel in otitis media?

A

Some travel cell to cell, most travel along in secretions

166
Q

What does pain and perforation of the eardrum stem from?

A

Damaged eustachian tube can’t move secretions from middle ear and pressure builds up - pressure on middle ear

167
Q

What can repeat infections of otitis media cause?

A

Hearing impairment

168
Q

What are the signs and symptoms of otitis media?

A
  • Earache - throbbing pain
  • Fever
  • Hearing difficulty
  • Headache
  • Irritability and trouble sleeping in infants
  • Congestion
  • Vomiting
169
Q

What exam confirms diagnosis of otitis media?

A

Signs and symptoms along with an otoscope exam

170
Q

What is the treatment of otitis media?

A

Antibiotics for bacterial etiology

Vaccine for S pneumoniae otitis media

171
Q

What is the epidemiology of otitis media?

A

Common in children, esp under age of 4

Millions of doctor visits annually

172
Q

What is the etiology of acute epiglottitis?

A

Haemophilus influenza type B
Haemophilus parainfluenza
Streptococcus pneumoniae

173
Q

What are the characteristics of Haemophilius influenza type B that causes acute epiglottitis?

A 
Gram negative
Small bacilli or coccobacilli
Capsule
Non motile
Endotoxin
174
Q

What is the reservoir of acute epiglottitis?

A

Humans

175
Q

What is the major virulence factor of acute epiglottitis?

A

Capsule

176
Q

What is the transmission method of acute epiglottitis?

A

Respiratory droplets

Normal flora can spread from nasopharynx to epiglottis maybe by secretions

177
Q

What is the pathogenesis of acute epiglottitis?

A
  • Arrives in epiglottis region
  • Replicates on surface
  • Capsule inhibits phagocytes
  • Growth and release of cytokines and inflammatory mediators results in cell damage and death
  • Cellulitis and inflammation of epiglottis
  • Edema and cellular debris obstruct air flow
178
Q

Is acute epiglottitis an obligate pathogen?

A

No - invasion is not obligatory for replication

179
Q

What happens when phagocytes are inhibited by a capsule?

A

Phagocytes die and release their contents - release of their chemical can cause further damage to host tissues

180
Q

Why is acute epiglottitis potentially fatal?

A

Edema and cellular debris can obstruct air flow

181
Q

What are the signs and symptoms of acute epiglottitis?

A

Begins with fever and sore throat

  • Enlarged cervical lymph nodes
  • Swelling of epiglottis
  • Bacteremia
  • Chills and shaking
  • Difficulty breathing
  • Abnormal breathing sounds like stridor
  • Dysphagia
  • Drooling
  • Cyanosis
182
Q

What position is child usually sitting in with acute epiglottitis?

A

Sitting position leaning forward with open mouth and protruding tongue

183
Q

Why must a physician take care in examining the throat with acute epiglottitis?

A

Swollen epiglottis can be sucked into edematous airway to cause total obstruction and suffocation

184
Q

How do we secure the airway with acute epiglottitis?

A

Intubation

185
Q

How do we diagnose acute epiglottitis?

A

Signs and symptoms along with identification of H influenzae

186
Q

What is the treatment for acute epiglottitis?

A

Antibiotics

Hospitalization and supportive care like intubation, humidifier, and anti-inflammatory meds, IV fluids

187
Q

What is the epidemiology of acute epiglottitis?

A

Very rare due to HIB (H influenza type B) vaccine

More common in developing world

188
Q

What is the etiology of oral candidiasis?

A

Candida albicans - dimorphic fungus

189
Q

Where is candida albicans located?

A

Yeast on mucosal surfaces as normal flora in mouth or vagina

190
Q

What form does candida albicans take in the invasive form?

A

Hyphae

191
Q

What is the reservoir of oral candidiasis?

A

Human as normal flora

192
Q

Why doesn’t oral candidiasis always present if it is part of the normal flora?

A

Usually kept in check by other bacterial flora and body defenses

193
Q

What is the number on pathogenic yeast?

A

Candida albicans

194
Q

What is the transmission method of oral candidiasis?

A

Endogenous source

195
Q

When would the normal flora be interrupted that makes room for a fungal infection like oral candidiasis?

A
  • Antibiotics
  • Immune response is suppressed - disease or cancer treatment
  • Immune response is not fully developed (infants) or declining (elderly)
196
Q

What are hyphae?

A

Elongated fungal cells - appear when candida become invasive and infectious

197
Q

What is the pathogenesis of oral candidiasis?

A

Opportunistic infection -
Normal flora that keep C albicans in check are diminished
C albicans flourishes and penetrates epithelium with psuedomycelia

198
Q

What are the signs and symptoms of oral candidiasis?

A
  • White, creamy overgrowth of tongue and mouth (cottage cheese appearance)
  • Lesions on tongue and mouth
  • Bleeding
  • Pain
  • Loss of taste
  • Cottony feeling
199
Q

How do we diagnose oral candidiasis?

A

Signs and symptoms and microscopy of stained cells (look for budding yeast)

200
Q

What is the treatment of oral candidiasis?

A

Topical or systemic antifungal agents

201
Q

What is the epidemiology of oral candidiasis?

A

Fairly common

  • Usually in infants and immunocompromised/immunosuppressed individuals
  • Diabetics
  • After prolonged broad spectrum antibiotics
202
Q

What is the etiology of diphtheria?

A

Corynebacterium diphtheriae

203
Q

What are the characteristics of Corynebacterium diphtheriae?

A 
Gram positive
Pleomorphic - rod, club shaped
Non motile
Non encapsulated
No endospores
Toxigenic or non toxigenic
204
Q

Where are nontoxigenic strains of Corynebacterium diphtheriae found?

A

Part of normal flora of URT

205
Q

Which strains of Corynebacterium diphtheriae cause diphtheria?

A

Toxigenic strains

206
Q

What is the reservoir for diphtheria?

A

Human URT

207
Q

What is the transmission method for diphtheria?

A

Repiratory droplet inhalation

Fomites to nasopharynx

208
Q

Where do fomites in diphtheria stem from?

A

From incubatory carriers, active cases, or people recoering from diphtheria

209
Q

How long can a person carry Corynebacterium diphtheriae after symptomatic disease?

A

Can carry for up to 2-3 months after symptoms subside

210
Q

What is the incubation period for diphtheria?

A

2-6 days

211
Q

What is the pathogenesis of diphtheria?

A
  • Colonize and adhere to pharynx (esp tonsilar region)
  • Bacteria multiplies on mucosal surface
  • Exotoxins produced causing disease - killing epithelium and phagocytes
  • Formation of ulcerous epithelium
  • Formation of false membrane
212
Q

Where does diphtheria colonize?

A 
Pharynx - especially tonsils
Larynx
Nose
Genital tract
Skin
213
Q

Does diphtheria pathogen invade deeper tissues?

A

No, stays on epithelial surface and replicates

214
Q

When does Corynebacterium diphtheriae produce toxin?

A

Only when infected with lysogenic phage carrying tox gene

215
Q

What is a tox gene?

A

Produces cytotoxin that inhibits protein synthesis in eukaryotes

216
Q

What is a phage?

A

A virus that infects bacteria - in diphtheria the viral DNA (tox gene) produces the toxin

217
Q

What covers the ulcerous epithelium of diphtheria?

A

Necrotic exudate

218
Q

How is the false membrane created in diphtheria?

A

Necrotic epithelium becomes embedded with RBCs, WBCs, bacteria, and fibrin - forms a psuedomembrane

219
Q

What structures are affected if a toxin of diphtheria is absorbed into the lymphatics and circulation?

A

Myocardium
Peripheral neurons
Kidney

220
Q

What conditions result in severe diphtheria?

A

Cardiac and kidney failure, death
If pharynx is involved, potentially fatal respiratory obstruction
Polynephritis

221
Q

How long does it take for diphtheria to resolve if not complications arise?

A

Resolves gradually

Membrane coughed up in 5-10 days

222
Q

What are the signs and symptoms of diphtheria?

A
  • Begins with mild sore throat
  • Low fever gets higher
  • Fatigue
  • Malaise
  • Drooling
  • Dysphagia
  • Dyspnea (stridor)
  • Bull neck
  • White/gray membrane over tonsils and throat
  • Ulcer
  • False membrane
223
Q

What is the bull neck appearance?

A

Swelling of neck due to localized inflammation and cervical lymph node enlargement

224
Q

What causes an ulcer in diphtheria?

A

Death of epithelial cells and phagocytes

225
Q

What does death of epithelial cells and phagocytes cause after an ulcer?

A

Ulcer is covered by necrotic exudate to form a false membrane

226
Q

What happens if an attempt is made to remove the false membrane?

A

Bleeding occurs

227
Q

How does the false membrane progress characteristically?

A

Soon becomes dark and ill smelling

228
Q

How far into the disease can signs of myocarditis be seen?

A

Usually within first two weeks

229
Q

What causes myocarditis in diphtheria?

A

When toxin gets to the heart

230
Q

How is diphtheria diagnosed?

A

Signs and symptoms
Lab culture on special selective/differential media
Microscopy

231
Q

What is the treatment for diphtheria?

A 
Isolation
Antibiotics
Diphtheria antitoxin (passive immunity)
IV fluids
Oxygen/intubation
232
Q

What is the epidemiology of diphtheria?

A

5-10 cases/year due to DPT vaccine
Common in developing world
Before 1935, number one killer of children in US due to infectious disease

233
Q

What is DPT?

A

Vaccine for diphtheria, pertussis, tetanus

From Flashcardlet (133 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions