Section 12 - LRTIs Flashcards
1
Q
What are symptoms of laryngitis/tracheitis?
A
- Hoarseness
- Burning pain
2
Q
What are common causes of laryngitis and tracheitis?
A
- Parainfluenza
- RSV
- Influenza
- Adenovirus
3
Q
What organism causes diphtheria?
A
Corynebacterium diphtheria
4
Q
What is unique about corynebacterium diphtheria?
A
It must be lysogenized to cause disease (must carry a viral genome)
5
Q
What does it mean to be lysogenized?
A
The virus is latent
6
Q
What are the 2 best diagnostic methods for a disease caused by corynebacterium diphtheria?
A
- PCR for the certain gene
- Look for presence of toxin with ELISA
7
Q
Will corynebacterium diphtheria with AB toxin cause disease?
A
No
8
Q
Why is diphtheria potentially life threatening?
A
- C diphtheria produces A and B proteins that stop protein synthesis, which causes cell death
- When cells die, they form a clump and the clump can grow and block the airway
9
Q
Where is diphtheria most common?
A
Developing world
10
Q
Is corynebacterium diphtheria found in the normal pharynx?
A
Yes, non-toxigenic strains
11
Q
How does corynebacterium diphtheria adhere to surfaces?
A
Pili or fimbriae
12
Q
What are 2 possible complications with diphtheria?
A
- Myocarditis
- Polyneuritis
13
Q
What is myocarditis?
A
Inflammation of the heart tissue
14
Q
What are symptoms of polyneuritis?
A
- Paralysis of soft palate
- Regurgitation of lipids
15
Q
How is diphtheria treated and why?
A
- With antitoxins and antibiotics
- Antibiotics lyse cells, so if they lyse viral cells the toxin will be released, so an antitoxin is needed
16
Q
What does DTAP provide vaccination against?
A
- Diphtheria
- Pertussis
- Tetanus
- Polio
- Haemophilus influenzae B
17
Q
What causes pertussis?
A
- Bordetella pertussis
- Bordetella parapertussis
18
Q
How is bordetella pertussis transmitted?
A
Airborne droplets
19
Q
What is the natural host of bordetella pertussis?
A
Humans
20
Q
How does bordetella pertussis cause infection?
A
Attaches to and multiples in ciliated respiratory mucosa
21
Q
What are the symptoms of an early bordetella pertussis infection?
A
Similar to a viral URT infection
22
Q
Is a fever common or uncommon in pertussis and what does this mean?
A
- Uncommon
- Pathogen causes a localized infection
23
Q
What are the toxins produced by bordetella pertussis?
A
- Pertussis toxin
- Adenylate cyclase
- Tracheal cytotoxin
24
Q
What does the A subunit of pertussis toxin do?
A
ADP-ribosyl transferase that catalyzes the transfer of ADP-ribose from NAD to host cell proteins
25
What does adenylate cyclase do?
Enters neutrophils and causes increased cAMP which inhibits chemotaxis, phagocytosis, and bactericidal killing abilities
26
What does tracheal cytotoxin do?
Kills tracheal epithelial cells
27
What are some possible complications of pertussis?
- Pneumonia (secondary infection)
- Alveolar rupture
- Seizures
28
What are the 3 stages of a pertussis infection?
1) Catarrhal
2) Paroxysmal
3) Convalescent
29
What are the symptoms of the catarrhal stage of a pertussis infection?
- Mild cold
- Runny nose
- Mild cough
30
How long can the catarrhal stage of a pertussis infection last?
Several weeks
31
What are the symptoms of the paroxysmal stage of a pertussis infection?
- Severe coughing
| - 15-25 paroxysmal fits/24 hours
32
When does the convalescent stage of a pertussis infection occur?
4 weeks after infection
33
What does it mean when a vaccine is acellular?
The entire bacterial cell isn't being used, only parts of the antigen are used
34
What is used in the vaccine against pertussis?
Pertussis toxoid and bacterial components
35
What are the common causes of viral acute bronchitis?
- Rhinovirus
- Coronavirus
- Influenza virus
- Adenovirus
36
What are the common causes of bacterial acute bronchitis?
- Bordetella pertussis
- Bordetella parapertussis
- Mycoplasma pneumoniae
- Chlamydophila pneumoniae
37
When does acute bronchitis normally occur?
After an URTI
38
What is sputum production indicative of?
Bronchitis
39
What is the primary cause of bronchiolitis and pneumonia in young infants?
Respiratory syncytial virus
40
How is RSV transmitted?
Droplets and sometimes hands
41
Where does RSV cause infection?
Nasopharynx and LRT
42
What are symptoms of RSV infection?
- Cough
- Fast respiratory rate
- Cyanosis
43
Which animal carries Sin Nombre virus (SNV)?
Deer mouse
44
How is SNV transmitted?
Inhalation of SNV-infected rodent feces, saliva, or urine
45
What happens to the body in an SNV infection?
- Viral invasion of pulmonary capillary endothelium
| - Fluid pours into lungs due to increased vascular permeability
46
What are the symptoms of old world hantavirus?
- Hemorrhagic fever
| - Renal syndrome
47
What is the criteria for an infection to be considered hospital acquired?
Patient must be in the hospital for at least 72 hours before getting the infection
48
What are the common causes of hospital acquired infections?
Gram negative organisms
49
What are the 4 routes for lung infection?
1) Upper airway colonization or infection that extends to lung
2) Aspiration of organisms
3) Inhalation of airborne droplets
4) Seeding of lung via blood from distant site
50
What is the maximum size that a droplet can be to reach the alveoli?
5 mm
51
Which organism causes pneumonia?
Many different organisms cause pneumonia based on different factors
52
What is the treatment for pneumonia?
No clear cut treatment; dependent on where the infection was contracted (community or hospital)
53
What are the 4 types of pneumonia?
1) Lobar
2) Bronchopneumonia
3) Interstitial
4) Lung abscess
54
What area does lobar pneumonia affect?
Distinct region of the lung
55
What area does interstitial pneumonia affect?
Lung interstitium
56
Is interstitial pneumonia normally viral or bacterial?
Viral
57
What area do lung abscess' affect?
Lung parenchyma
58
What are common causes of bacterial pneumonia?
- Streptococcus pneumoniae (25-60%)
| - Haemophilus influenzae (5-15%)
59
What is special about Haemophilus influenzae?
Frequently colonizes the URT of bronchitic patients
60
What is primary atypical pneumonia?
- New event (not a secondary infection)
- Strep pneumoniae is not the cause
- Infection doesn't respond to penicillin
61
What are common causes of primary atypical pneumonia?
- M. pneumoniae
- Chlamydophila psittaci
- Coxiella burnetti
- Legionella pneumophila
62
How are chlamydophila psittaci and coxiella burnetti acquired?
Infected animals
63
How is legionella pneumophila acquired?
Contaminated environmental sources
64
How is primary atypical pneumonia diagnosed?
- Sputum that is collected in the morning before breakfast
- Gram stain
- Serology to confirm diagnosis
65
What is the difference between sputum and spit?
Spit contains epithelial cells (if a sample contains more than 10 epithelial cells it is considered spit)
66
Where does sputum come from?
Lungs
67
What is the treatment for primary atypical pneumonia?
Antibiotics
68
How can primary atypical pneumonia be prevented?
- 23-valent pneumococcus capsular vaccine for adults
| - 7-valent vaccine for infants
69
What does it mean when a vaccine is called 15-valent?
It protects against 15 different strains of the organism
70
Can viruses cause pneumonia?
Yes
71
How can viruses can pneumonia?
Invade through the respiratory tract or blood
72
What can influenza A cause?
Epidemics and pandemics
73
What species is influenza A found in?
Birds
74
What can influenza B cause?
Epidemics
75
What can influenza C cause?
No epidemics, just a mild respiratory illness
76
Which types of influenza are put in vaccines?
A and B
77
What type of antigens do influenza viruses contain?
H and N
78
Is antigenic shift or drift more common in influenza viruses?
Drift
79
Why do new influenza strains emerge?
Because influenza virus A infects pigs, horses, and other mammals
80
Are pandemics usually caused by new or pre-existing organisms?
New
81
How does influenza virus enter the body?
- Droplets
| - Attaches to sialic acid receptor on epithelial cell surface via H-spikes
82
How long does it take to see symptoms after being infected with influenza?
1-3 days
83
What can occur after 7-10 days of being infected with influenza?
Bronchitis or interstitial pneumonia
84
How is the influenza virus prepared?
- Virus is grown in egg
- Purified
- Formalin is inactivated
- Ether is extracted
85
What is the alternative influenza vaccine for people that are allergic to eggs?
"Split" vaccine (purified H and N antigens)
86
How is an influenza infection treated?
Antiviral agents (zanamivir and oseltamivir)
87
How can an influenza infection be diagnosed?
PCR
88
What is SARS-CoV?
Severe acute respiratory syndrome associated coronavirus
89
What does SARS-CoV cause?
15% of cold-like infections
90
How is SARS-CoV acquired?
Consumption of exotic animals
91
How long is SARS-CoV stable at room temperature?
2 days
92
How long is SARS-CoV stable in feces?
4 days
93
What is MERS and how is it transmitted?
- A new form of coronavirus
| - Transmitted through human-to-camel contact
94
Where are outbreaks of MERS seen?
Saudi Arabia
95
Where are receptors for MERS found in the body?
Lower respiratory tract
96
What causes tuberculosis?
Mycobacterium tuberculosis
97
How long is mycobacterium tuberculosis stable on a surface?
Weeks
98
How does mycobacterium cause disease?
- Hides in alveolar macrophages
- Once macrophages start presenting TB Ags, the body starts to mount a response against the TB-containing macrophages
- This causes granuloma, which can rupture so the organism can gain access to other parts of the body
99
What is mycobacterium tuberculosis resistant to?
- Acid fast staining
| - Disinfectant
100
How is tuberculosis diagnosed?
- Signs and symptoms
| - Tuberculin test
101
What are the signs and symptoms of tuberculosis?
- Coughing producing a lot of sputum
- Fever
- Weight loss
- Blood in sputum
102
What occurs in a tuberculin test?
Standardized amount of purified protein derivative is injected intradermally and the reaction is read 48 hours later
103
What is a positive result for the tuberculin test in immunocompetent individuals?
Induration of 10 mm or more
104
What is a positive result for the tuberculin test in immunosuppressed individuals?
Induration of 5 mm or more
105
People with tuberculosis often are also infected with ______
HIV
106
What is the treatment for tuberculosis?
3 drugs in combination for 6-9 months
107
What is cystic fibrosis?
An inherited disease of secretory glands
108
What are symptoms of cystic fibrosis?
- Pancreatic insufficiency
- Abnormal sweat electrolyte concentrations
- Production of very viscous bronchial secretions
109
What are common organisms that colonize the lungs of cystic fibrosis patients?
- P. aeruginosa
- S. aureus
- B. cepacia
110
What is the treatment for cystic fibrosis?
Lung transplant
