UR viral Flashcards
1
Q
What is the temperature that upper respiratory viruses replicated?
A
33-35 C
2
Q
What is the most common viral infection of the upper respiratory tract?
A
Rhinovirus
3
Q
What are the symptoms of the common cold? What are not?
A
Rhinitis
Pharyngitis
No high fever, respiratory tract involvement
4
Q
What is the incidence of colds?
A
2-3/year for adults, 6-8/yr for child
5
Q
What are the three major complications associated with the common cold?
A
OM
Sinus infection
Asthma exacerbation
6
Q
What should always be included in the dx for chronic upper respiratory tract infections?
A
Allergies
7
Q
What are the four most common causes of the common cold in order?
A
- Rhinovirus (most)
- Coronavirus
- Other known
- Unidentified
8
Q
Rhinoviruses are members of what family? What type of genome? What are the three viral species? Are they enveloped?
A
Picronavirus
+ssRNA
A, B, C
No envelope
9
Q
How are rhinoviruses spread?
A
Respiratory secretions
10
Q
How much virus is needed for inoculation?
A
Very small amount
11
Q
What is the incubation period for rhinoviruses?
A
1-3 days
12
Q
True or false: rhinoviruses do not exacerbate asthma or COPD?
A
False
13
Q
What is the MOA of rhinovirus?
A
- attach to cilia
- disrupt epithelial cell layer
- fluid outpouring from the LP
14
Q
What are the treatments for rhinovirus? When are abx indicated?
A
Symptom management
Abx only if there is an associated bacterial infx
15
Q
Why is it hard to get immunity to rhinoviruses?
A
Over 100 serotypes
16
Q
Is there any vaccine for rhinoviruses? If so, which serotypes?
A
No–too many serotypes
17
Q
What is the genomic make up of corona viruses? Enveloped? Where do they replicate?
A
+ ssRNA
Enveloped.
Replicate in the epithelial cells of the upper respiratory tract
18
Q
What is the optimal temp for Non-SARS coronaviruses? SARS one? What is the significance of this?
A
33-35 C for non
37 for SARS
This explains the differing symptoms
19
Q
Transmission of the coronavirus through what?
A
Large droplets
20
Q
What is the incubation period of coronavirus?
A
3 days
21
Q
What is the treatment for infx with coronavirus? Is there a vaccine? If so, which serotypes?
A
symptomatic
No vaccine
22
Q
What is the only common cold virus that has a DNA genome? Is it enveloped?
A
Adenovirus (dsDNA)
Non-enveloped
23
Q
What is the surrounding halo around adenoviruses?
A
Toxins
24
Q
What are the most common adenoviruses that cause respiratory disease?
A
1, 2, and 5
25
Individuals can shed adenoviruses for how long?
18 months
26
Where can adenoviruses survive where other viruses cannot? What is the significance of this?
Lymphoid tissue--allows a longer period to shed
27
Which of the upper respiratory tract viruses have no seasonal pattern of disease?
Adenovirus
28
What is the cause of pharyngealconjunctival fever?
Adenovirus
29
Serotypes 40 and 41 or adenovirus cause what diseases?
GI diseases
30
Are there vaccines to adenovirus? If so, for which serotypes?
yes, one for serotypes 4 and 7
31
What is the viral cause of croup, bronchiolitis, and penumonia?
Paravirus
32
Rhinoviruses infect which cells?
The ciliated mucosal epithelial cells.
33
Early in an infection with rhinovirus, nasal secretions are primarily due to what? Later?
Initially increased vascular permeability
Later d/t increase in lactoferrin, lysozyme, and IgA
34
The damage caused by viral infections and predispose patients to bacterial infections how? (2)
Interruption of mucociliary escalator
| Weakened immune system
35
Why is it possible to get reinfected with a coronavirus?
We develop poor immunity to the virus
36
What is the treatment for infection with adenoviruses?
Symptomatic
37
Do you developed good immunity to adenoviruses?
Yes, but there are so many serotypes
38
What is the family of coxsackieviruses? Are they enveloped? What is their genetic material?
Subfamily of picornaviruses
Non-enveloped
+ssRNA
39
Where can coxsackie viruses survive, where other viruses cannot?
GI tract (can survive low pH)
40
What is the mode of transmission for coxsackie viruses?
Fecal-oral route
41
Are there vaccines available for the coxsackie virus? If so, which serotypes?
None
42
What is the prognosis for infection with coxsackie viruses?
Full recovery in a few weeks
43
What is the viruses that causes herpangina?
Coxsackie virus
44
What are the symptoms of herpangina? (2)
Abrupt fever
| Small vesicles on soft palate.
45
What are the possible complications associated with herpangina?
Meningitis or encephalitis
46
What is the virus that causes hand-foot-and mouth disease? Symptoms? (2)
Coxsackie
Fever
Vesicular lesions on the soles of the hands, feet, and in oral areas.
47
What are all the viruses that cause the common cold? (6)
1. Rhinovirus
2. Non-SARS corona
3. Adenovirus
4. Coxsackie
4. Parainflu (B &C)
5. Respiratory syncytial virus
6. Flu
48
What is the only common cold virus that is not caused by droplets?
Coxsackie
49
What is the only dsDNA virus that causes the common cold?
Adenovirus
50
What are the symptoms of croup? (3)
Fever, seal's bark, inspiratory stridor
51
What is the prodrome for croup?
Rhinorrhea, mild cough, pharyngitis
52
What are the complications for croup?
Hypoxia
53
Why is croup more worrisome in children?
Smaller airway
54
What are the two things that should be in your differential when seeing croup?
1. Obstruction
| 2. Bacterial epiglottitis
55
What is the treatment for uncomplicated croup?
Humidified air
56
What is the treatment for complicated croup?
Oxygen
Epi
Glucocorticoids
57
What is the test for differentiating between complicated and uncomplicated cases of croup?
Stridor at rest
58
What is the most common virus that causes croup?
parainfluenza (serotype 1)
59
The parainfluenza virus is from what family? Enveloped? Genome type?
From paramyxovirus fam
Helical nucleocapsid + envelop
-ssRNA
60
How is parainfluenza virus transmitted?
Droplets
61
What is the incubation period for parainfluenza virus?
2-10 days
62
In which cells does the parainfluenza virus replicate?
ciliated epithelium
63
How long does immunity against parainfluenza virus last?
Short lived
64
What are the major symptoms of the flu that are different from the common cold?
1. Myalgias
2. Shaking chills
3. HA
4. cough
65
What is the incubation period for the flu?
2 days
66
What is the biggest complication associated with the flu?
Pneumonia
67
Primary influenza virus pneumonia is caused by which flu strain?
A
68
What will you see in a patient's sputum gram stain if they have viral pneumonia?
High PMNs, but no significant number of bacteria
69
What is the fatality rate of viral pneumonia?
50%
70
When in a flu infection do symptoms of pneumonia develop?
1-4 days following symptoms
71
What will a CXR reveal about viral pneumonia?
Diffuse interstitial infiltration
72
When do bacterial influenza associated pneumonias develop?
1 week after onset of symptoms
73
What are the causative agents of bacterial pneumonia? (3)
1. Strep penumonia
2. Staph aureus
3. H. influenzae
74
Why are individuals who recently have been sick with a virus more likely to develop pneumonia?
Damage to the mucociliary escalator or respiratory epithelium
Compromised immune function
75
The flu is a member of what family of viruses? Is it enveloped? What is the genetic make up?
Orthomyxovirus family
Enveloped
Segmented -ssRNA
76
What are the proteins that the flu virus expresses? What does each do?
Hemagglutinin (attachment protein)
| Neuraminidase (Cleaves sialc acid to aid in release)
77
What is antigenic drift? How does this apply to the flu? How does it happen?
Small changes in H and N proteins brought about by point mutations made by polymerase
78
What is antigenic shift? How does this apply to the flue? How does it happen?
Large changes in H and N proteins, driven by reassortment of two viruses (segment reassortment)
79
What is the cause of having to change the flu vaccine every year (antigenic shift or drift)?
Antigenic drift
80
How does segment reassortment occur?
Segments of two different viruses that have infected the same cell rearrange as new virions are formed
81
How many segments does the flu virus have?
7 - 8
82
How are the different hemagglutinin and neuraminidase protein variants distinguished from one another?
Different number (e.g. H3N2)
83
The flu virus is a - ssRNA virus. What does it need in it in order to carry out replication?
An RNA dependent RNA pol. (RdRp)
84
Where does flu virus reassortment occur?
In pigs (they're called "mixing vessels")
85
Which part of the flu virus are the dominant targets for antibodies?
Hemagglutinin and Neuraminidase
86
In viral naming (e.g. A/Texas/1/77/(H3N2), what does each component stand for?
```
A = serotype
Texas = location
1 = isolate
77= year
H3N2 = protein subtypes
```
87
What is the host range for influenza type A?
Humans, pigs, birds, other animals
88
What is the host range for influenza type B?
Just humans
89
What is the host range for Influenza type C?
Humans and pigs
90
What is the severity level for influenza type A, B, and C respectively?
```
A = severe
B = sometimes severe
C = mild
```
91
Which influenza type has the ability to cause pandemics? Epidemics?
```
Pandemics = A
Epidemics = A and B
```
92
What is the only influenza strain that can undergo genetic shift?
A
93
For mild or uncomplicated cases of the flu, what is the determining factor on whether to treat with antivirals or not?
Based on risk factors for the patient
94
For a patient with no risk factors, when should you administer antivirals for the flu?
within 48 hours of onset
95
For a patient with risk factors, when should you administer antivirals for the flu?
Always
96
What are the ion channel blocking medications used for the flu? (2)
Amantadine
| Rimatadine
97
What is the MOA of ion channel blockers?
block the viral M2 ion channel that is required for virus release
98
How long does the seasonal flu last?
about 1 week
99
When are the ion channel blocking antivirals used for the flu?
For type A, but not anymore d/t resistance
100
What are the three neuraminidase inhibitors?
Zanamivir
Oseltamivir
Peramivir
101
What is the MOA of neuraminidase inhibitors?
Neuraminidase
inhibitors block the neuraminidase enzyme of influenza A and B viruses, thereby reducing the
ability of the virus to spread from cell-to-cell
and to move through the mucus in respiratory
secretions.
102
What is the route of administration of zanamivir?
oral inhalation
103
What is the route of administration of oseltamivir?
Oral
104
What is the route of administration of peramivir?
IV
105
Neuraminidase inhibitors are effective against which flu strains?
A and B
106
What are the three varieties of flu vaccine?
Inactivated (IM)
Live attenuated
Recombinant flu
107
How are inactivated flu virus vaccines prepared? How are these administered?
"Killed" via formeldehyde
IM or ID
108
What is the age group that should get IM inactivated influenza vaccine?
Greater than 6 mo, including those with chronic medical disease
109
What is the age group that should get ID inactivated influenza vaccine?
18-64
110
What is the age group that should get live attenuated influenza vaccine?
healthy, non-pregnant 2-49 yo
111
What is the age group that should get IM recombinant influenza vaccine?
18-49
112
What is the route of administration for the live, attenuate virus flu vaccine?
Intranasal
113
What is the agent in the recombinant flu vaccine?
Hemagglutinin protein
114
What is the advantage of producing a vaccine from mammalian cells (MDMK)?
1. Rapid scale up
| 2. Reduced likelihood of egg issues
115
What are the advantages of live attenuated vaccine?
IgG production, cell mediated immunity
116
How is the recombinant influenza vaccine made? Is this egg free?
a baculovirus is
reengineered to produce appropriate influenza
hemagglutinin (HA) proteins within cultured
insect cells.
This is egg free
117
Antiviral chemoprophylaxis is
| indicated for whom?
high risk populations
118
What are the strains that are in the trivalent vaccines? quadravalent?
2 As and a B = trivalent
2 As and 2 Bs = quadraavalent
119
The SARS virus is from which family?
The coronavirus
120
What type of genetic material is in the SARS coronavirus? Is it enveloped?
+ssRNA
| Enveloped
121
How is the SARS virus transmitted?
Fecal oral route
122
What is the incubation period for the SARS virus?
2-10 days
123
What are the symptoms of bronchiolitis? (3)
1. Expiratory wheezing
2. Nasal flaring/Subcostal retractions
3. Variable fever
124
What is the more common cause of bronchiolitis and pneumonia in children <1 yo?
Respiratory syncytial virus (RSV)
125
RSV is from what virus family? Is it enveloped? What is the genetic material?
Paramyxovirus fam
Enveloped
-ssRNA
126
How is RSV spread? Incubation period? Duration?
Droplets
4-5 days incubation
2 weeks duration
127
What is the antiviral that can be used for RSV? What is the MOA?
Ribavirin
| Guanosine analogue that promotes mutation of the viral genes
128
The F protein of RSV can lead to the
| activation of what immune system protein?
TLR4
129
What are the two prophylactic treatments for RSV?
Palivizumab
| RSIG = (IVIG)
130
What is the MOA of palivizumab? (what is it)
Monoclonal antibody to RSB
131
When is prophylaxis for RSV indicated?
Premature births
| <2 yo with chronic lung disease
132
What is the route used for Ribavirin?
Aerosol
133
Once symptoms of RSV have begun, are RSIG or palivizumab effective in treatment?
No
