Test 3: Wk11: 1 Respiratory Viral Infections - Bogomolnaya Flashcards
1
Q
— are members of the orthomyxovirus group
A
influenza
2
Q
enveloped, single-stranded negative-sense segmented RNA viruses
A
Influenza
3
Q
3 major types of influenza viruses
A
A, B, C
4
Q
influenza types are based on antigenic differences in
A
their ribonucleoprotein (NP) and matrix protein antigens (M)
5
Q
major influenza epidemics caused by
A
influenza A
6
Q
— infect a wide variety of species including mammals and birds and have a tendency to undergo significant antigenic changes
A
Influenza A
7
Q
— are more antigenically stable and are known to infect humans and seals, occur in more localized outbreaks
A
Influenza B
8
Q
— viruses appear to be relatively minor cause of disease effecting humans and pigs
A
Influenza C
9
Q
two Influenza virus-specified glycoproteins
A
hemagglutinin (HA or H)
Neuraminidase (NA or N)
10
Q
ratio of H to N
A
4 or 5 to 1
11
Q
integral membrane protein in Influenza A known as —
A
M2 ion channel protein
12
Q
integral membrane protein in Influenza B known as —
A
NB, functions as ion channel
13
Q
how does influenza C differ from A and B
A
posses only 7 RNA segments and has no N
it does have receptor-destroying capability
14
Q
the hemagglutinin of Influenza C does what
A
binds to a different receptor than A and B
15
Q
Named because of its ability to agglutinate red blood cells from certain species
A
Hemagglutinin
16
Q
It is the viral attachment protein, responsible for binding to sialic acid on epithelial cell surface receptors, which is a critical first step in initiating infection of the cell
A
Hemagglutinin
17
Q
Is an antigenic hydrolytic enzyme that acts on the hemagglutinin receptors by splitting off their terminal neuraminic acid
A
Neuraminidase
18
Q
promotes a smooth passage for the virus in the
respiratory tract by inactivating mucoprotein receptors in respiratory
secretions
A
Neuraminidase
19
Q
destroys viral receptor, thus preventing aggregation
and superinfection in infected cells
A
Neuraminidase
20
Q
has a major role in viral release from infected cells
A
Neuraminidase
21
Q
Influenza gene segments
A
A- 8
B- 8
C- 7
22
Q
Influenza unique proteins
A
A- M2
B- NB
C- HEF
23
Q
Influenza A host range
A
humans, swine, birds, equines, marine mammals, bats
24
Q
Influenza B host range
A
humans and seals
25
Influenza C host range
humans, swine
26
most unique aspect of Influenza A
ability to develop a wide variety of subtypes through the processes of mutation and whole gene “swapping” between strains, called reassortment.
27
Which influenza virus experiences drifts and shifts
a
28
Antigenic Drift
mutations acquired over long period of time
29
Antigenic drift
reassortment of genome segments, rapid and unpredictable
30
Three hemagglutinins ---, ---, and --- and two neuraminidases --- and --- appear to be of greatest importance in human
infections.
H1, H2, H3
N1, N2
31
human influenza viruses are --- in the environment and sensitive to heat, acid pH, and solvents.
in general not stable
32
--- retain infectivity for several weeks outside the host
avian influenza viruses H5N1
33
Influenza viruses most common mode of transmission
direct droplet
34
where do Influenza viruses replicate
in upper respiratory tract ciliated epithelial cells causing structural and functional abnormalities.
35
Influenza viruses block
Block in host cell syntheses, release in lysosomal
enzymes, and desquamation of ciliated and mucous
producing cells.
36
most protective antibody for influenza viruses
Anti-hemagglutinin, has the ability to neutralize virus on re-exposure because it is a surface protein easily recognized by the antibody
37
--- is a serious complication of influenza viruses most common in infants and children
Reye Syndrome, develops 2-12 days after onset of infection
38
Influenza bacterial superinfection most commonly caused by
Streptococcus pneumoniae,
| Haemophilus influenzae, and Staphylococcus aureus.
39
3 ways influenza viruses can cause death
1. underlying disease with decompensation
2. Superinfection
3. Direct rapid progression
40
Influenza Diagnosis Techniques (5)
virus culture
serology
rapid antigen and molecular (viral nucleic acid) assays
immunofluorescence
reverse transcription polymerase chain reaction (RT PCR)
41
avoid --- in influenza
aspirin
42
does antibiotic prophylaxis help preventing superinfections
no
43
Neuraminidase inhibitors,
| --- and --- , are useful for influenza A and B
oseltamivir, zanamivir
44
--- or --- blocked virus uncoating and assembly
Amantadine or rimantadine
45
Three types of flu vaccines are produced in the United States:
egg based, cell based, and recombinant
46
--- viruses belong to the paramyxovirus group
Parainfluenza
47
Parainfluenza cause
mild cold like symptoms but can also cause serious
| respiratory tract disease.
48
There are four serotypes of parainfluenza viruses:
1, 2, 3, and 4.
49
These enveloped viruses contain linear (nonsegmented),
| negative sense, single stranded RNA genome.
Parainfluenza
50
Similar to influenza viruses, parainfluenza viruses possess
a hemagglutinin and neuraminidase, but on the same spike.
51
Parainfluenza viruses differ from the influenza viruses in that RNA synthesis occurs in the --- rather than in the ---.
cytoplasm; nucleus
52
The single stranded, negative sense linear RNA genome is bound to a
nucleoprotein (helical nucleocapsid), and the matrix protein surrounds
the nucleoprotein complex, which is packaged into a lipid bilayer
envelope containing attachment protein (H and N on the same spike)
and the fusion protein (F).
Parainfluenza
53
are parainfluenza viruses stable? do they have antigenic drift or shift?
relatively stable with no drift or shift
54
parainfluenza viruses cause serious disease in
infants and young children
55
most common parainfluenzas
1 and 3
56
--- immunity plays an important role in controlling parainfluenza virus infection.
Humoral
57
Parainfluenza viruses onset
may be abrupt; usually begins as a mild URI and progress over 1-3 days to middle and lower respiratory tract
58
Parainfluenza virus duration
4 - 21 days; usually 7 - 10
59
--- is the major cause of acute croup (laryngotracheitis) in infants and young children, but also causes less severe diseases such as mild URI, pharyngitis, and tracheobronchitis in individuals of all ages.
Parainfluenza 1
60
Parainfluenza 1 outbreaks occur
during fall
61
of slightly less significance. It has been associated with croup, primarily in children, with mild URI, and occasionally with acute lower respiratory disease.
Parainfluenza 2
62
Parainfluenza 2 outbreaks occur
during fall
63
--- is a major cause of severe lower respiratory disease in infants and young children.
Parainfluenza 3
64
It often causes bronchitis, pneumonia, and croup in children younger than 1 year of age.
Parainfluenza 3
65
In older children and adults, it may cause URI or tracheobronchitis.
Parainfluenza 3
66
Parainfluenza 3 outbreaks occur
during any season
67
It is generally associated with mild upper respiratory illness only.
Parainfluenza 4
68
Parainfluenza viruses control and therapy
there is none
69
Parainfluenza viruses treatment
relieve sx by using OTC medications
70
Parainfluenza viruses diagnosis (3)
RT-PCR, antigen Assay, Virus isolation
71
RSV stands for
Respiratory Syncytial Virus
72
--- belongs to
Pneumovirus of the
Paramyxovirus group.
Respiratory syncytial virus (RSV)
73
It is an enveloped, negative
sense linear RNA virus that primarily infects the
bronchi, bronchioles, and alveoli of the lung.
RSV
74
does RSV have hemagglutinin or neuraminidase
no
75
The RNA genome is linear (
| nonsegmented ), negative sense, and single stranded and codes for at least 10 different proteins.
RSV
76
The virion structure is similar to parainfluenza virus except that the envelope glycoproteins are an attachment (G) protein and a
fusion (F) protein.
RSV
77
nucleoprotein bound to genomic RNA (helical
nucleocapsid), a phosphoprotein and two matrix (M) proteins in
the viral envelope.
RSV
78
The virion also contains the viral RNA polymerase enzyme
RSV
79
RSV replicates in the --- and buds out from the plasma membrane.
cytoplasm
80
In RSV Two envelope glycoproteins (spikes), G and F, mediate
attachment and syncytium formation, respectively
81
RSV Subtypes
A and B
| A is more severe
82
is the most important respiratory virus that causes a severe infection in infants
RSV
83
is the major cause of bronchiolitis and pneumonia in infants under 1 year of age
RSV
84
is the leading cause of hospitalization in US children, with annual hospitalization rates of 6 per 1000 children younger tha n
5 years.
RSV
85
RSV Outbreaks
community outbreaks occur annually from late fall to early spring
last 8-12 weeks with 50% of families with children
86
RSV duration
The usual duration of virus shedding is 5 to 7 days; young infants, however, may shed virus for 9 to 20 days or longer.
87
Nosocomial infection reduced by
careful handwashing
| masks are not helpful
88
RSV is spread to the upper respiratory tract by
contact with infective secretions.
89
The pathologic effect of RSV is mainly caused by --- , which is followed by immunologically mediated cell injury.
direct viral invasion of the respiratory epithelium
90
RSV Viral surface --- protein plays an important role in pathogenesis by forming syncytia and multinucleated giant cells leading to
cell death.
F
91
Infection with RSV results in -- and --- humoral and secretory antibody responses. However, immunity to reinfection is brief.
IgG and IgA
92
in RSV Vaccination with killed vaccine appears to
enhance the severity of subsequent disease.
93
RSV Leads to
bronchiolitis and pneumonitis with cough, wheezing, and respiratory distress
94
RSV Clinical Findings (3)
hyperexpansion of lungs, hypoxemia, hypercapnia
95
RSV causes of death
Causes of death include respiratory failure, right
| sided heart failure, and bacterial superinfection.
96
is there a vaccine for RSV
no
97
RSV prophylaxis in high risk infants
Monoclonal antibody to protein F
98
HMPV stands for
Human Metapneumovirus
99
--- is Pneumovirus of paramyxovirus group, was discovered in 2001 and can cause upper and lower respiratory tract infection in people of all age groups.
HMPV
100
--- is a significant cause of ARD in infants and young children.
HMPV
101
Infection with HMPV generally occurs in
slightly older children compared to RSV that infects younger children.
102
HMPV incubation period
3-6 days
103
HMPV symptoms
fever, nasal congestion, cough, and shortness of breath, which may progress to bronchiolitis or pneumonia
104
HMPV diagnosis
RTPCR
viral antigen enzyme immunoassay
immunofluorescence
The virus culture is rarely done
105
HMPV treatment
no specific treatment available
106
--- are naked capsid, icosahedral, and double
| stranded DNA viruses.
Adenoviruses
107
7 subgroups of Adenovirus
A-G
108
The virion size is in the range of 90 to 100 nm and it contains
a linear double stranded DNA genome covered with an
icosahedral capsid.
Adenovirus
109
Adenovirus Capsid
The capsid is composed of 252 subunits (capsomeres), including 240
hexons and 12 pentons and fibers.
110
Adenoviruses enter cells via
--- and replication occurs in the --- by using host RNA polymerase for transcription and viral DNA dependent DNA polymerase (viral DNA polymerase) for replication of DNA genomes.
viropexis; nucleus
111
How are adenovirus virions released
cell destruction
112
Adenovirus infection route
Infects by droplet, oral route, or direct inoculation.
113
After the acute phase of illness, the viruses may remain in tissues, particularly lymphoid structures such as tonsils, adenoids, and intestinal Peyer patches, and may become reactivated and shed without producing illness for 6 to 18 months thereafter.
adenovirus
114
Integration of --- into the host cell genome has been shown to occur; this latent state can persist for years in tonsillar tissue and peripheral blood lymphocytes.
adenoviral DNA
115
Penton projections are toxic to cells
Adenoviruses
116
adenovirus death protein
is considered important
| for efficient lysis of infected cells and release of newly formed virions.
117
adenovirus immunity
Immunity to adenoviruses after infection is serotype
| specific and usually long lasting.
118
adenovirus symptoms
Symptoms include fever, rhinitis, pharyngitis, cough, and conjunctivitis.
119
Adenovirus diagnosis
Diagnosis by PCR, antigen detection, virus isolation or serology
120
adenovirus treatment
there is no specific treatment
121
--- may be effective for severe adenovirus infections
Cidofovir
122
adenovirus vaccine
Live enteric vaccine containing serotypes 4 and 7 is used in military
123
They are small (20
30 nm), naked capsid virus particles containing single
stranded, positive sense RNA genomes.
Rhinovirus
124
The receptor for most rhinoviruses (and some coxsackieviruses) is ---
glycoprotein intercellular adhesion molecule 1 (ICAM-1)
125
most common cold virus
Rhinovirus
126
Lower respiratory tract disease caused by rhinoviruses
is uncommon.
127
Rhinovirus infections occur when
Rhinovirus infections may be seen at any time of the year. Epidemic peaks tend to occur in the early fall or spring months.
128
Rhinovirus transmission
Transmission occurs by hand
| to hand, hand to eye, or hand to object to hand ( eg , doorknob) contamination.
129
--- can survive for hours on contaminated environmental surfaces. Self
inoculation after hand contamination may be a
more important mode of spread than that by airborne particles.
Rhinoviruses
130
Rhinovirus incubation period
The usual incubation period is 2 to 3 days, and acute symptoms commonly last 3 to 7 days.
131
Rhinoviruses can be diagnosed by
viral genome amplification by RTPCR in nasopharyngeal specimens.
132
contain a positive sense single stranded linear RNA genome,
which is surrounded by an envelope that includes a lipid bilayer derived from
intracellular rough endoplasmic reticulum and Golgi membranes of infected
cells.
Coronaviruses
