Exam2Lec8RNAviruses Flashcards
1
Q
What is the genome and sense of picornavirus
A
RNA genomes and positive sense, ss
2
Q
What is the capsid symmetry of picornavirus
A
Iscoahedral capsid symmetry
3
Q
Where is the replication of picornavirus
A
Cytoplasmic
4
Q
T/F picornavirus has variable host range
A
True
5
Q
What is the illness of picornavirus
A
Respiratory, GI, cardiac, hepatic illness
“common cold” (rhino, entero)
6
Q
What are the exact examples we do for class?
A
Rhinovirus (HRV14)
EV-D68
Poliovirus
7
Q
What is the tropism of entero-
A
GI tract (includes coxsackie A,B and echo)
8
Q
What is the tropism for coxsackie
A
A: skin, mucous membranes
B: heart, lungs, liver
9
Q
What is the tropism for Rhino-
A
URT
10
Q
What is the tropism for Hep A
A
Liver
11
Q
What does the picornavirus family cause?
A
Respiratory, GI, cardiac, hepatic illness
12
Q
Positive stranded viral genomic RNA is what?
A
mRNA and considered infectious
13
Q
What allows the facilitates interaction with ribosomes
A
Viral RNA has a 5’ internal ribosome entry site (IRES) sequence that facilitates interaction with ribosomes.
14
Q
What is the problem and resolution of single segment?
A
Problem: single gene
Resolution: viral protease
- Clips polyprotein into smaller functional subunits
15
Q
What is an example of viral protease?
A
Poliovirus
3c=protease
16
Q
What is not capped in genomic RNA , and has what instead?
A
5’ end of genomic RNA is not capped, instead has viral VPg protein bound
17
Q
What is the structure of Rhinovirus
A
ss(+) RNA, icosahedral
Serotypes:>200
18
Q
What is the transmission of Rhinovirus
A
Fomite
Respiratory (surgical / N95)
Sensitive to low pH
Cannot grow above 33oC ⭐️
19
Q
What is the seasonality of Rhinovirus
A
Peaks in Fall (predominant), Spring
More severe infection in Winter
20
Q
When you see rhinovirus, what should you think?
A
Common colds
Makes up 1/3 to 1/2 of all acute respiratory infection in humans
21
Q
What is the common cold symptoms
A
Coryza/rhinitis: congestion, runny nose
Pharyngitis: sore throat
Cough
Low-grade fever, if any
22
Q
Causes of common cold
A
Rhinoviruses
Coronaviruses
Parainfluenza viruses
23
Q
What should be used for large droplets
A
surgical mask
24
Q
what should be used for small droplets
A
N95
25
Common cold is what type of illness
Common cold is a self-limited illness.
26
Common colds account for how many respiratory infections in humans
one-third to one-half
27
What is the virus that is similar to rhinoviruses
Enterovirus D68
28
What is the structure of Enterovirus D68
Structure: ss (+) RNA, icosahedral
29
What does Enterovirus can cause
EV-D68 can cause mild to severe respiratory illness.
Mild symptoms may include fever, runny nose, sneezing, cough, and body and muscle aches.
Severe symptoms may include wheezing and difficulty breathing.
Linked to acute flaccid myelitis (AFM) ⭐️
30
What is unique to EV-D68 disease
Linked to acute flaccid myelitis (AFM) ⭐️
31
What is seasonality in Enterovirus D68
Peaks In summer.fall
- earlier than rhinovirus
32
Where has the EV D68 have been recently
US Europe and Asia
33
What does poliovirus infect
Infects cells in the gut/intestinal lining, specifically the associated lymphoid tissue (GALT)
34
What are the symptoms of Poliovirus
Typically, asymptomatic infection (~70%)
Mild symptoms: sore throat, fever, malaise (~25%)
Rare CNS involvement: aseptic meningitis
Can progress to poliomyelitis
35
What is unique about poliovirus
Rare CNS involvement: aseptic meningitis
Can progress to poliomyelitis
36
What is poliomyelitis
virus targets CNS= paralysis
37
What is the poliovirus vaccine in the US
4 doses of inactivated polio vaccine (IPV, Salk)
38
What does the current vaccine (US) prevent?
ONLY POLIOMYELITIS, not infection
39
What is the polio vaccine out if the US
Live attenuated vaccine (OPV)
Bivalent (Types 1 and 3): Type 2 eradicated in 1999
40
What is the problem of the live attenuated vaccine out of US
can cause circulating vaccine- derived poliovirus (cVDPV)
- mostly type 2
41
Where is poliovirus endemic in?
Pakistan and Afghanistan
42
What is the Genomes of caliciviruses family
RNA Genomes
43
what is the sense of caliciviruses family
positive sense, ss
44
What is the capsid symmetry of Caliciviruses Family
Icosahedral
45
What is the replication of caliciveuses family
Cytoplasmic
46
What is host range of Caliciviruses family
narrow host range
47
what illness does Caliciviruses family cause
GI illness
48
What is the most common cause of viral gastroenteritis
Noroviruses
49
what is common in Noroviruses
Family and community outbreaks common (cruise ship outbreaks)
Especially in closed communities, e.g. day care
50
T/F Noroviruses is not age limited like rotavirus
True
Incidence is highest in children < 5 yo
Severe gastroenteritis in elderly (> 65 yo)
51
What is the transmission of Noroviruses
Fecal oral route
52
What is the family of rotavirus
Reovirus family
53
What is the genome of rotavirus
DsRNA
54
What is the structure of rotavirus?
Icosahedra
DOUBLE LAYERED
55
What is special of rotavirus?
Ds RNA
DOUBLE LAYER
56
Where does rotavirus replicate?
replicates in cytoplasm
57
What is the predominant group of rotavirus
group A
58
what time of the year is rotavirus more predominant
winter month
59
More SERVE gastroenteritis than other GI pathogens
Rotavirus
60
rotavirus causes ___ severe gastroenteritis than other GI pathogens
more
61
What group of people are more severe
8 – 10% of all diarrhea; 35 – 40% of diarrhea requiring hospitalization
Most severe in children 4 – 23 months
62
How is Rotavirus transmitted
Fecal-oral transmission
63
What is the incubation period of rotavirus
Incubation period 1-3 days
64
What is the clinical characteristic of rotavirus ?
Characteristic clinical triad (vomit, diarrhea and fever)
----Abrupt onset
vomiting (1-3 d) then diarrhea (5-8 d)
----low grade fever
65
Where do you see fatal disease of rotavirus
Severe fatal disease in malnourished or immune suppressed
Resource poor countries - a leading cause of infant mortality
66
What is the prevention of rotavirus
Vaccine live, attenuated recombinant (RotaShield)
---Approved for use in 1999
----Removed from market in late 1999 due to problems with intussuception
Current vaccines
---RotaTeq® (RV5) 3 doses at 2, 4, and 6 months
----Rotarix® (RV1) 2 doses at 2 and 4 months
GOOD HYGIENE
67
Details about negative strand viruses
genomic RNA is complementary sense of mRNA
Viral genomic RNA cannot direct virus life cycle.
-- must be first transcribed into mRNA.
Thus, the genome is not infectious when introduced into cells. (in contrast to positive-sense viruses)
68
What are the primary features of (-) strand viruses
Gene expression regulated by internal transcriptional initiation from negative-strand template.
Viruses must package functional polymerases in virions.
Negative-sense viruses can have multiple segments in their genome.
Many “emerging” viruses are negative-strand!!
69
What - sense must have?
Viruses must package functional polymerases in virions.
70
What are the nonsegmented negative sense RNA viruses
filoviruses: Ebola, Marburg
paramyxoviruses: measles, mumps
71
What are the segmented negative sense RNA viruses
orthomyxoviruses: influenza A, B, C
72
For paramyxoviruses what is the genome and sense
RNA genome
negative sense, ss (~ 15 kb)
73
What is the caspsid symmetry of paramyxovirus
Helical
encapsidated
74
What is the replication of paramyxovirus
Cytoplasmic
75
what is the host range of paramyxovirus
Narrow host range
76
What is the illness of paramyxovirus
respiratory and neurologic illness
77
Paramyxovirus gene expression
1.Transcription by viral polymerase (L and P).
2. Single promoter at 3´ end.
3. Linear array of genes.
4. Each gene bounded by transcription initiation and transcription termination signals. ⭐️
5. Sequential transcription of genes.
6. Transcriptional attenuation due to polymerase dissociation at gene junctions (gradient of expression). ⭐️
78
How does disease state of measles vary among areas
Temperate areas : Mild disease
Tropical areas: Severe disease
79
what is the incubation period of measles and the symptoms
Incubation up to 2 weeks
Prodromal stage to rash 2-3 days with running eyes and nose
---Koplik spots (enanthem): rash in mouth
---Rash starts in face and migrates to trunk: Maculopapular eruption
---Temperature rises to ~40⁰C
---Bronchitis and pneumonitis (rales)
80
What is the transmission of measles
Droplets enter respiratory tract or eye
81
What is the prodromal stage of measles
Primary replication on respiratory epithelial cells
- bronchitis and pneumonities (rales)
-running eyes and nose
-high fever
82
Where does measles replicated in the body (primary and secondary)
Primary replication on respiratory epithelial cells
Secondary replication in mononuclear cells (lymph nodes)
83
Measles is shed in what ?
Shed in body fluids
84
What can measles secondary replication in mononuclear cells cause
Causes leukopenia
85
What is responsible for pathogenesis of rash in measles
Cytotoxic T cells
86
What plays a role in pathogenesis and severity of measles
Giant cell formation
87
What is major reason for killing children with measles? how does this happen
secondary infection
measles kills are memory cells so susceptible for second infection
88
The virus travels to body surfaces and causes what?
kopek spots (enanthem)
Maculopapular rash (face to trunk)
89
What is unique about the rash of measles
face to trunk
90
What is the lung infection of measles
temporary respiratory illness
91
What is the oral mucosa infection of measles
Koplik's spots
92
What is the skin infection of measles
maculopapular rash
93
What is the overall impact of measles
Transient generalized immunosuppression
2 infections
94
For Filoviruses what is the genomes and sense
RNA genomes
single strand, negative sense (~19kb)
95
For Filoviruse family what is the genomes and sense
RNA genomes
single strand, negative sense (~19kb)
Longest genome of any negative sense virus
96
What is the caspid symmetry for filoviruse family
encapsulated, helical capsid symmetry
filamentous
97
What is the replication of filoviruse family
cytoplasmic
98
What does filoviruses family cause
acute infection
99
extra details of filoviruses
Tropism for monocytes, hepatocytes, endothelial cells
Receptor (EBOV): Niemann-Pick C1
100
When does ebola symptoms appear?
Symptoms may appear anywhere from 2 to 21 days after exposure to Ebola virus, although 8-10 days is most common.
101
How does ebloa spread?
one person to another through direct contact with blood, urine, saliva, feces, vomit, semen and needles
102
who has the highest risk of Ebola
Healthcare works, family, friends and others who come into close contact with ebola infected patients
103
What does elbow primarily infects ?
Endothelia cells, dendiritic cells and macrophages
104
What happens with endothelial cell infection
hemorrhage and organ failure
105
What happens with dendritic cells infection
decrease immune system
106
What happens with macrophages infection
Induces release of excess cytokines (cytokine storm) which causes systemic inflammation
107
What is the genome of Orthomyxozovirus family
RNA genome
neg sense
ss
encapsulated
8 SEGMENTS
108
What is the capsid symmetry of orthomyxovirus family
Helical
109
What are the two types of particles that orthomyxovirus family can cause
spherical and filamentous
110
what is the replication of orthomyxovirus family
nuclear replication ⭐️
111
what does the orthomyxovirus family cause
respiratory illness
112
What is in the orthomyxovirus family
Influenza
113
How many types of Influenza is there
3 human types
-immunize : A and B
-C is not problematic
114
When does synpotims begin for Influenza
1-4 days after infection
115
when is the infectious phase of Influenza
1 day before 3-4 days after symptoms begin
116
What are the symptoms of Influenza
sudden onset of chills and fever
sore throat, dry cough
fatigue and malaise
myalgia headaches dizziness
diarrea
bronchitis pneumonia
117
How long is recovery of Influenza and due to what
recovery takes 1-3 weeks after viral clearance due Tod damage left behind
118
What is the vital attachment of Influenza
HA (hemagglutinin)
119
What is the enzyme that cleaves the hemagglutin
NA (neuraminidase)
120
What is antigenic drift and shift
drift: accumulation of point mutations (small changes ) to Influenza surface antigens (HA and NA)
shift:reassortment of genomic segment (big change) leading to entirely different surface antigen (HA and NA)
121
what is responsible of influenza epidemics?
antigenic drift
