Respiratory Viral infections Flashcards
1
Q
disease in upper respiratory tract
A
common cold
2
Q
diseases in lower respiratory tract
A
bronchitis, bronchiolitis, pneumonia
3
Q
most pneumonia (affects alveoli) are usually caused by –
A
bacteria
4
Q
when viruses invade respiratory tract cells they trigger –
A
inflammation
5
Q
the small airways of young children can be significantly be narrowed by –
A
inflammation that causes swelling
6
Q
pneumonia is due to inflammation caused by –
A
virus itself or bacterial infection developed due to viral inflammation
7
Q
common causes of common cold
A
rhinovirus (picorna-)
coronavirus
adenovirus
8
Q
less common cause of common cold
A
influenza (orhomyxo-)
9
Q
two types of picornaviridae
A
enterovirus and rhinovirus
10
Q
smallest RNA virus
A
picornaviridae
11
Q
is the picornaviridae (entero and rhino) enveloped?
A
no
12
Q
how is rhinovirus spread?
A
contaminated objects and aerosols
13
Q
how to prevent rhinovirus?
A
frequent hand washing
14
Q
enterovirus infect –
A
GI tract
15
Q
why is it hard to make a vaccine for common cold?
A
rhinovirus has many types
16
Q
what is the significance of rhinovirus being non-enveloped?
A
survive outside for a long time
17
Q
why is rhinovirus limited to the upper respiratory tract?
A
doesn’t like cold
18
Q
is there an anti-rhinovirus drug?
A
no
19
Q
why is there no anti-rhino drug?
A
too late to give drugs when you have symptoms = already peaked
20
Q
is the coronavirus enveloped?
A
yes
21
Q
coronavirus has a – genome
A
RNA
22
Q
types of coronavirus
A
SARS and MERS
23
Q
SARS =
A
severe acute respiratory syndrome
24
Q
MERS =
A
middle east respiratory syndrome
25
how does coronavirus spread?
aerosols
26
why can rhinovirus be spread by contaminated objects?
it's non-enveloped
27
why is coronavirus limited to upper respiratory tract?
it doesn't like the cold
28
if coronavirus infects enteric tract -->
diarrhea (usually infants)
29
is there an anti-coronavirus drug?
no
30
is there a coronavirus vaccine?
no
31
unlike typical human coronaviruses, SARS and MERS infections involve --
lower respiratory tract
32
consolidated lung is more -- than aerated lung parenchyma
radiopaque
33
pneumonia
liquid in alveolar space (instead of gas)
34
new syndrome in late 2002 in southern China (last outbreak was 2004 lab)
SARS
35
unlike SARS, MERS virus shows no signs of --
easy spread
36
coronavirus could be found in --
bats
37
bats --> for MERS
camels
38
bats --> for SARS
civets
39
adenovirus as -- genome
dsDNA
40
Is adenovirus enveloped?
no
41
who are at risk for adenovirus?
military recruits and boarding schools
42
Is there an anti-adenovirus drug?
no
43
is there a vaccine for adenovirus?
yes,
| type 4 and 7 vaccine for military recruits
44
number one cause of common cold
rhinovirus
45
prevalence of common cold among age groups
children > adults > adults over 60
46
Are older adults more likely to get a common cold or flu?
flu
47
common cause of bronchitis
parainfluenza (paramyxo-)
48
common cause of bronchiolitis
RSV (paramyxo-)
49
common viral cause of pneumonia
RSV
parainfluenza
influenza (othomyxo-)
50
children are most at risk for which pneumonia causing viruses
RSV and parainfluenza
51
everyone is at risk for -- causing pneumonia because there are many different strains
influenza
52
Paramyxoviridae viruses
parainfluenza and RSV
53
paramyxoviridae has -- genome
RNA
54
is paramyxoviridae enveloped?
yes
55
paramyxoviridae (parainfluenza and RSV)attaches with --
glycoprotein
56
paramyxoviridae (parainfluenza and RSV) has -- to envelope host cell membrane
fusion protein
57
fused cell membrane
syncytia (paramyxoviridae)
58
major cause of severe respiratory infection in 3 y/o and younger
paramyxo = parainfluenza and RSV
59
what is the number one cause of infantile bronchiolitis/pneumonia?
RSV
60
RSV has -- symptoms in older children and adults
milder
61
antiviral drugs for RSV
ribavirin (nucleoside analogue)
62
who uses ribavirin
premature and immunocompromised infants at high risk for RSV
63
prevent RSV for high risk groups (premature and immunocompromised infants)
RespiGam and Synagis
64
RespiGam is a pooled human serum containing --
anti-RSV antibody (for prevention)
65
what is synagis?
antibody against F protein of RSV (for prevention)
66
Spanish flu
H!N1
67
Asian flu
H2N2
68
Hong Kong flu
H3N2
69
even if flu doesn't work on you it reduces -- in a pop
of carriers
70
how many segments does influenza virus have?
8
71
is the influenza virus enveloped?
yes
72
HA of influenza
attachment
73
NA of influenza
virion release
74
M2 of influenza
uncoating
75
type A influenza
mammals and birds
76
type B influenza
mammals
77
type C influenza
mammals
78
which influenza type doesn't cause disease
C
79
which influenza types have vaccines?
A and B
80
influenza's HA protein binds to -- on epithelial cell surface receptors
sialic acid
81
what promotes the fusion of the influenza envelope to the cell membrane
HA protein
82
What forms the proton channel for influenza?
M2 protein
83
the proton channel formed by the M2 protein promotes -- of the envelope contents to break the protein-protein interactions to allow uncoating and delivery of the nucleocapsid into the cytoplasm
acidification
84
influenza virus reduces -- of the respiratory tract thereby increasing bacterial infection
natural defenses
85
virus first targets and kills -- causing loss of host's primary defense system
mucus-secreting, ciliated and other epithelial cells
86
influenza's -- facilitates the dev of the infection by cleaving sialic acid residues of the mucus thereby providing access to tissue
NA
87
if the influenza virus spreads to the lower respiratory tract, the infection can cause -- of bronchial or alveolar epithelium down to a single-cell basal layer or BM
severe desquamation (shedding)
88
high risk groups for pneumonia
young and elderly
immunocompromised
chronic medical conditions (diabetes)
89
non-pulmonary complications of influenza for children
CNS involvement
90
non-pulmonary complications of influenza for elderly
cardiac (myocarditis, pericarditis)
91
extreme life threatening immune response complication of influenza
sepsis
92
two anti-flu immunity
flu-specific antibody and flue-specific cytotoxic lymphocytes
93
-- inhibits HA protein and offers future protection from influenza
flu-specific antibody
94
why vaccine didn't work for flu?
antigen drift
95
antigen drift is a -- process so vaccine strains must be updated
continuous
96
antigen drift involves -- so minor changes in HA/NA results in outdated antibodies
errors during RNA replication
97
two different strains or virus form a new subtype
antigen shift
98
direct transmission of animal influenza A to humans is an example of --
antigen shift
99
-- leads to outbreak
antigen drift
100
-- leads to pandemics
antigen shift
101
antigen shift involves -- that lead to major changes in HA/NA
genetic reassortment
102
pandemics = new, spreading -- but not necessarily deadly
globally
103
what is the natural reservoirs for influenza
aquatic birds
104
influenza A: what is usually an intermediate host between reservoir birds and humans
pigs
105
Do humans commonly get infected with influenza A from domestic bird intermediates?
no
106
-- occurs in the intermediate host (pig) for influenza A virus
gene reassortment (pig = mixing vessel)
107
most deadly subtypes of avian influenza for birds
H5 and H7
108
H5N1 (avian influenza) killed 70-100% of chickens in --
Hong Kong farms
109
Does avian influenza infect humans easily?
no
110
human-to-human transmission of avian version of HA is --
rare
111
how do humans acquire avian influenza
exposures to infected poultry, feces, or contaminated dust/soil
112
route for amantadine
oral
113
route for rimantadine
oral
114
route for Tamiflu (oseltamivir)
oral
115
route for Relenza (azamivir)
inhalation
116
target of amantadine
M2 (uncoating)
117
target of rimantadine
M2 (uncoating)
118
target of Tamiflu (oseltamivir)
NA (budding)
119
target of Relenza (zanamivir)
NA (budding)
120
anti-flu drugs for type A and B
Tamiflu and relenza
121
anti-flu drugs for type A only
amantadine and rimantadine
122
which anti-flu drugs prevent virion release
Tamiflu and relenza
123
which drugs prevent viral uncoating
amantadine and rimantadine
124
influenza vaccine is a killed virus grown in eggs
killed virus
125
flu vaccine has -- protective effects
short-lived
126
influenza vaccine that is grown in eggs and is cold-adapted
live attenuated
127
since live attenuated flu vaccine is cold adapted it can't --
replicate in lungs (limited to upper tract)
128
examples of live attenuated flu vaccine
FluMist (nasal spray)
129
who can use live attenuated flu vaccine?
healthy people
130
effectiveness of flu vaccine
60%
131
live attenuated flu vaccine is associated with --
mucosal immunity
