Viruses: RNA Positive Sense Viruses Flashcards
1
Q
List the RNA positive sense viruses
A
- Poliovirus
- Coxsackievirus A
- Coxsackievirus B
- Rhinovirus
5 Hepatitis A - Norovirus/Norowalk Virus
- Hepatitis C
- Coronavirus
- HIV
- Echovirus
- West Nile Virus
- Yellow Fever Virus
- Dengue Fever
2
Q
Picornaviridae Virus Family
A
a family of viruses that includes hepatitis A virus, poliovirus, coxsackievirus A and B, echovirus, and Rhinovirus
3
Q
picornaviruses (i.e. hepatitis A virus, poliovirus, coxsackievirus A and B, echovirus, Rhinovirus) are
A
- positive-sense RNA viruses
2. naked viruses
4
Q
hepatitis A virus, poliovirus, coxsackievirus A and B, and echovirus (picornaviruses) are transmitted
A
fecal-orally (Rhinovirus is transmitted via respiratory droplets)
5
Q
the genetic material of positive-sense RNA viruses (such as picornaviruses) is structured like
A
like mRNA and can be directly translated into viral protein products
6
Q
the whole genome of picornaviruses (i.e. hepatitis A virus, poliovirus, coxsackievirus A and B, echovirus, Rhinovirus) is translated into
A
one long polyprotein that is cleaved by host and viral proteases
7
Q
hepatitis A virus
A
a positive sense-RNA virus in the Picornaviridae family
8
Q
the Enterovirus genus (positive-sense RNA viruses in the Picornaviridae family) includes
A
poliovirus, coxsackievirus A and B, echovirus, and rhinovirus
9
Q
Rhinovirus
A
a positive-sense RNA virus in the Picornaviridae family
10
Q
hepatitis A virus can cause
A
liver inflammation (hepatitis), gastroenteritis, and hepatosplenomegaly
11
Q
poliovirus
A
a positive-sense RNA virus in the Picornaviridae family
12
Q
coxsackievirus A and B
A
positive-sense RNA viruses in the Picornaviridae family
13
Q
echovirus
A
a positive-sense RNA virus in the Picornaviridae family
14
Q
enteroviruses are the number one cause of
A
aseptic meningitis
15
Q
aseptic meningitis (caused by viruses such as enteroviruses (i.e. poliovirus, coxsackievirus A and B, and echovirus)) presents with
A
a normal CSF glucose level
16
Q
aseptic meningitis (caused by viruses such as enteroviruses (i.e. poliovirus, coxsackievirus A and B, and echovirus)) is a
A
self-limited inflammation of the meninges in which a virus, not bacteria, is the causative agent
17
Q
aseptic meningitis (caused by viruses such as enteroviruses (i.e. poliovirus, coxsackievirus A and B, and echovirus)) presents with an
A
elevated CSF protein level
18
Q
viral meningitis caused by enteroviruses (i.e. poliovirus, coxsackievirus A and B, and echovirus) most commonly affects
A
children
19
Q
Rhinovirus infection affects the
A
upper respiratory tract and is spread via respiratory droplets
20
Q
poliovirus
A
- a positive-sense
- RNA virus
- in the Picornaviridae family
- naked virus
- acid-stable
21
Q
replication of poliovirus occurs in
A
cells of the gut mucosa (such as Peyer’s patches)
22
Q
poliovirus affects
A
motor neurons of the anterior horn of the spinal cord
23
Q
paralysis seen in poliovirus infection is typically
A
asymmetric
24
Q
muscle weakness caused by poliovirus can lead to
A
respiratory failure
25
poliovirus can cause
aseptic meningitis
26
the Salk vaccine
the Salk vaccine is an inactivated (killed) vaccine administered by injection to prevent polio
27
the attenuated Sabin vaccine is
the attenuated Sabin vaccine is administered orally to elicit production of both IgG and IgA antibodies against poliovirus
28
coxsackievirus A and B Virus
1. a positive-sense
2. RNA virus
3. in the Picornaviridae family
4. naked virus
29
coxsackievirus A
a positive-sense RNA virus in the Picornaviridae family
30
coxsackievirus A causes
coxsackievirus A causes hand, foot, and mouth disease, which presents with a red, vesicular rash in the mouth, on the fingers and palms of the hands, and the soles of the feet
31
coxsackievirus A can cause
aseptic meningitis
32
coxsackieviruses commonly affect
young children during summer months
33
coxsackievirus B
a positive-sense RNA virus in the Picornaviridae family
34
coxsackievirus B can cause
myopericarditis leading to dilated cardiomyopathy
35
coxsackievirus B causes
Bornholm disease (also known as the devil’s grip or epidemic pleurodynia), which is characterized by severe, unilateral pleuritic pain in the lower chest
36
Rhinovirus
1. a positive-sense
2. RNA virus
3. in the Picornaviridae family
4. naked virus
5. acid labile
37
Rhinovirus is transmitted via
1. respiratory droplets
| 2. contact with people or fomites
38
hand washing reduces the risk of contracting or spreading Rhinovirus by transmission via
fomites (inanimate objects such as toys, door handles, and faucets)
39
Rhinovirus binds
Rhinovirus binds the ICAM-1 (intercellular adhesion molecule 1) protein of host cells for cellular entry
40
Rhinovirus replicates more efficiently in temperatures around
33ºC
41
Rhinovirus causes
upper respiratory tract infections
42
there are roughly _____ different serotypes of Rhinovirus
there are roughly 100 different serotypes of Rhinovirus
43
hepatitis A virus
1. a positive-sense
2. RNA virus
3. in the Picornaviridae family
4. naked virus
5. acid stable
44
hepatitis A virus causes
liver inflammation (hepatitis), gastroenteritis, and hepatosplenomegaly
45
hepatitis A virus is transmitted
fecal-orally
46
water contaminated with hepatitis A virus can be purified by
chlorination, bleach, UV irradiation, or boiling
47
contaminated water is a common source of
hepatitis A virus in developing countries
48
contaminated shellfish are a common source of
hepatitis A virus in developed countries
49
hepatitis A virus infection is commonly seen in
travelers in areas where HAV is endemic
50
hepatitis A virus infection can cause
nausea, vomiting, and abdominal pain
51
hepatitis A virus infection often presents with
jaundice
52
anicteric hepatitis
anicteric hepatitis (hepatitis without jaundice) is more likely to be seen young children and infants infected with hepatitis A virus
53
smokers with hepatitis A often develop
an aversion to smoking
54
the duration of hepatitis A symptoms typically last around a
month
55
hepatitis A is often a
self-limiting infection
56
hepatitis A has no
carrier or chronic state
57
the hepatitis A vaccine is an
inactivated (killed) vaccine
58
Norovirus/Norwalk virus
1. positive sense
2. RNA virus
3. Caliciviridae family
4. naked virus
59
the whole genome of Norovirus/Norwalk virus is translated into
one long polyprotein that is cleaved by host and viral proteases
60
Norovirus/Norwalk virus outbreaks commonly occur in
1. places where people are in close quarters (i.e. cruise ships)
2. day care centers and schools
61
Norovirus/Norwalk virus infection is associated with
consumption of contaminated shellfish
62
Norovirus/Norwalk virus can cause
explosive watery diarrhea
63
flaviviruses (i.e. hepatitis C virus, West Nile virus, Yellow fever virus, Dengue virus) are
1. RNA viruses
2. Positive sense viruses
3. enveloped
64
flaviviruses
1. hepatitis C virus
2. West Nile virus
3. Yellow fever virus
4. Dengue virus
65
the genomes of flaviviruses (i.e. hepatitis C virus, West Nile virus, Yellow fever virus, Dengue virus) contain
a single RNA segment
66
Dengue virus
1. RNA viruses
2. Positive sense viruses
3. enveloped
4. flaviviridae
67
the _____ is the vector of Dengue virus
aedes mosquito
68
type 2 dengue fever is alternatively called
breakbone fever
69
classic dengue fever can progress to
classic dengue fever can progress to dengue hemorrhagic fever in severe cases, leading to thrombocytopenia and spontaneous bleeding
70
dengue fever can lead to
acute renal failure
71
Yellow fever virus
1. RNA viruses
2. Positive sense viruses
3. enveloped
4. flaviviridae
72
the ______ is the vector of Yellow fever virus
Aedes mosquito
73
yellow fever often presents with
jaundice
74
yellow fever can present with
muscle pain, especially severe backache
75
yellow fever is a
yellow fever is a hemorrhagic fever and can cause spontaneous bleeding in the gastrointestinal tract and mucous membranes (including the nose, mouth, and eyes)
76
Yellow Fever Vaccine
a live attenuated vaccine can be administered to prevent yellow fever (especially important for those traveling to Africa and South America)
77
West Nile virus
1. RNA viruses
2. Positive sense viruses
3. enveloped
4. flaviviridae
78
______ are the reservoir for West Nile virus
birds
79
_____ are the vectors of West Nile virus
Culex spp. mosquitoes
80
West Nile virus infection can have manifestations, including
1. encephalitis
2. viral meningitis
3. flaccid paralysis
4. seizures
5. coma
81
hepatitis C virus
1. RNA viruses
2. Positive sense viruses
3. enveloped
4. flaviviridae
82
hepatitis C virus can cause
liver inflammation and damage (hepatitis), which can result in jaundice
83
hepatitis C virus can be transmitted via
1. exposure to infected blood (i.e. sharing needles or blood transfusions)
2. sharing needles or needlestick injuries
84
the envelope proteins of the hepatitis C virus exhibit
antigenic variation
85
the virion-encoded RNA polymerase of hepatitis C virus
the virion-encoded RNA polymerase of hepatitis C virus lacks proofreading exonuclease activity in the 3’-5’ direction, making it prone to frequent mutations → antigenic variation
86
hepatitis C virus can cause
liver inflammation and damage (hepatitis), which can result in jaundice
87
60-80% of patients infected with hepatitis C virus develop
chronic infection
88
hepatitis C virus can cause
1. cirrhosis
| 2. hepatocellular carcinoma (usually after development of cirrhosis)
89
ALT in hepatitis C
ALT will be elevated during the acute stage of hepatitis C virus infection and fall after 6 months
90
hepatitis C virus infection is associated with
hepatitis C virus infection is associated with mixed cryoglobulinemia (development of predominantly IgM immunoglobulins that precipitate at colder temperatures)
91
Treatment of Hepatitis C
ribavirin is used in combination therapy with interferon alpha to treat hepatitis C virus infection
92
protease inhibitors block replication of hepatitis C virus by
protease inhibitors block replication of hepatitis C virus by preventing cleavage of proteins vital for producing infectious forms of the virus
93
togaviruses
1. Eastern Equine Encephalitis
2. Western Equine Encephalitis
3 Venezuelan Equine Encephalitis
4. Rubella virus
94
togaviruses (i.e. Eastern/Western/Venezuelan equine encephalitis virus, Rubella virus) are
1. RNA Viruses
| 2. Positive sense
95
Togaviruses in the Alphavirus genus (i.e. Eastern/Western/Venezuelan equine encephalitis virus) are
arboviruses (viruses that are arthropod-borne)
96
Arboviruses
viruses that are arthropod borne
97
Alphavirus Genus
1. Eastern Equine Encephalitis
2. Western Equine Encephalitis
3 Venezuelan Equine Encephalitis
98
_______ are common vectors of togaviruses (i.e. Eastern/Western/Venezuelan equine encephalitis virus, Rubella virus)
mosquitoes
99
Western equine encephalitis virus (WEEV), Eastern equine encephalitis virus (EEEV), and Venezuelan equine encephalitis virus (VEEV) cause
encephalitis
100
Rubella
rubella (or the German measles) is a childhood exanthem caused by Rubella virus
101
Rubella virus, Western equine encephalitis virus (WEEV), Eastern equine encephalitis virus (EEEV), and Venezuelan equine encephalitis virus (VEEV) are
enveloped
102
Rubella virus
1. positive sense
2. RNA virus
3. Togaviridae family
103
rubella can present with
tender postauricular and occipital lymphadenopathy
104
rubella typically presents with a
distinctive maculopapular rash that begins on the face and spreads inferiorly
105
Rubella virus is transmitted via
respiratory droplets
106
Rubella virus can be transmitted
vertically
107
Rubella viruses are a _____ infection
TORCHeS
108
The classic triad of symptoms seen in congenital rubella
1. patent ductus arteriosus
2. congenital cataracts
3. sensorineural deafness
109
congenital rubella may present with
1. blueberry muffin rash
| 2. jaundice
110
rubella in adults may present with
arthritis or arthralgias of the knees, wrists, and fingers
111
the measles, mumps, and rubella (MMR) vaccine is
the measles, mumps, and rubella (MMR) vaccine is a live attenuated vaccine administered to prevent rubella (as well as measles and mumps)
112
______ is a contraindication for the MMR vaccine
pregnancy
113
the live attenuated MMR vaccine should only be administered to HIV-positive patients who have a
CD4+ count >200
114
the whole genome of togaviruses (i.e. Eastern/Western/Venezuelan equine encephalitis virus, Rubella virus) is translated into
one long polyprotein that is cleaved by host and viral proteases
115
Coronaviridae
1. positive sense
2. RNA Virus family
3. enveloped
116
the capsules of coronaviruses are
helical
117
coronaviruses can cause the
common cold
118
coronaviruses can cause
upper respiratory infections that can lead to SARS or MERS (and even acute respiratory failure)
119
Human immunodeficiency virus (HIV)
1. positive sense
2. RNA virus
3. Retroviridae family
4. enveloped
120
if left untreated, HIV infection can lead to
acquired immunodeficiency syndrome (AIDS)
121
HIV is a
diploid virus; each HIV virion is composed of two copies of positive-sense RNA
122
the gag gene of HIV
encodes the p24 protein (thousands of p24 protein products comprise the conical capsid of HIV)
123
the env gene of HIV
1. the env gene of HIV encodes the gp41 and gp120 envelope proteins
2. the env gene encodes HIV envelope proteins, including the transmembrane protein gp41
3. the env gene encodes HIV envelope proteins, including the surface protein gp120
124
the pol gene of HIV
the pol gene of HIV encodes a reverse transcriptase (an RNA-dependent DNA polymerase), which converts RNA to DNA
125
HIV initially infects
macrophages
126
HIV infects
CD4+ helper T-cells
127
acute HIV infection
acute HIV infection (or HIV prodrome) frequently presents with flu or mono-like symptoms such as cervical lymphadenopathy and pharyngitis
128
acute HIV infection (or HIV prodrome) frequently presents with
fever
129
CD4+ helper T-cells (which are targeted by HIV) are
CD4+ helper T-cells (which are targeted by HIV) are white blood cells (lymphocytes)
130
HIV undergoes
HIV undergoes a clinical latent period (or incubation period) that can last up to 10 years
131
a ______ is the diagnostic marker of AIDS
a CD4+ count <200 is the diagnostic marker of AIDS
132
patients with HIV are at a higher risk of
patients with HIV are at a higher risk of some cancers, such as diffuse large B-cell lymphoma
133
HIV gains entry into host cells via
1. the CCR5 receptor in early stages of infection
| 2. the CXCR4 receptor in later stages of infection
134
ELISA and HIV
detects the presence of anti-HIV antibodies (ELISAs are used to screen for HIV)
135
______ are used to screen for HIV
ELISAs
136
_______ is done to confirm HIV infection in patients who tested positive on an ELISA screening test
a western blot (which detects the p24 antigen) is done to confirm HIV infection in patients who tested positive on an ELISA screening test
137
nucleotide/nucleoside reverse transcriptase inhibitors (NRTIs) are
non-functional nucleotide analogs that prevent the elongation of DNA molecules synthesized by HIV’s reverse transcriptase (NRTIs are incorporated into the DNA chain)
138
_______ should be used for pregnant HIV patients to reduce the risk of transmitting HIV to the fetus
Zovudine
139
non-nucleoside/nucleoside reverse transcriptase inhibitors (NNRTIs) block
non-nucleoside/nucleoside reverse transcriptase inhibitors (NNRTIs) block the reverse transcriptase enzyme of HIV so that the reverse transcription of RNA to DNA cannot occur (NNRTIs are not incorporated into the DNA chain)
140
NRTIs and NNRTIs are
reverse transcriptase inhibitors
141
protease inhibitors block replication of HIV by
protease inhibitors block replication of HIV by binding proteases and preventing cleavage of proteins that are vital for producing infectious forms of the virus
142
______ blocks the CCR5 host cell membrane protein, preventing HIV from fusing with the host cell
maraviroc
