RNA +sense Flashcards
(116 cards)
1
Q
RNA + SENSE VIRUSES
A
Picornaviridae
Togaviridae
Flaviviridae
Calciviridae
Coronaviridae
2
Q
Enveloped RNA positive sense
A
Togaviridae
Flaviviridae
Coronaviridae
3
Q
RNA PROPERTIES
A
● RNA is labile and transient
● Most RNA viruses replicate in the cytoplasm
● Cells cannot replicate RNA. RNA viruses must encode an RNA-dependent RNA
polymerase
4
Q
Genome structure of RNA determines?
A
mechanisms of transcription and replication
5
Q
REMINDER‼️
RNA viruses are prone to mutation
A
6
Q
RNA VIRUS
The genome structure polarity determine
A
how viral messenger RNA (mRNA) is generated and proteins are processes RNA viruses
7
Q
REMINDER‼️‼️
RNA viruses, except for (+) RNA genome, must carry polymerases.
A
8
Q
REMINDER‼️‼️
ALL (-) RNA viruses are envelope
A
9
Q
_________________ resembles mRNA and is translated into a polyprotein which is proteolyzed.
A
(+) RNA genome
10
Q
Positive sense uses __________ for replication
A
(-) RNA template
11
Q
What viruses? early proteins are translated from the genome and late proteins from smaller mRNAs transcribed from template
A
togaviruses
coronaviruses
caliciviruses
12
Q
(-) RNA
A
Orthomyxoviruses
Paramyxoviruses
Rhabdoviruses
Filoviruses
Bunyaviruses
13
Q
is a template for individual mRNAs
A
(-) RNA genome
14
Q
Required for replication in negative sense rna
A
full-length (+) RNA template
15
Q
What virus replicate and transcribe in the nucleus, and each segment of the genome encodes one
mRNA and is a template
A
Orthomyxoviruses
16
Q
(+/-) Segmented RNA genome is a template for mRNA (+RNA)
A
Reovirus
17
Q
genome is converted into DNA, which is integrated into the host chromatin and transcribed as a cellular gene
A
Retrovirus
18
Q
Picornavidae size
A
Aprrox. 30
19
Q
Picornaviridae disease
A
Cardioviruses
Polioviruses (coxsackie viruses)
Parechoviruses
Enteroviruses
Hepatitis A
Rhinoviruses
20
Q
from the Italian word piccolo, meaning “small”
A
Picornaviridae
21
Q
Picornaviridae genome structure
A
Single-stranded positive-sense RNA viruses
22
Q
Among the simplest of the RNA viruses
A
Picornaviridae
23
Q
Highly structured capsid that has limited surface elaboration
A
Picornaviridae
24
Q
Picornaviridae family includes
A
enteroviruses
RVs
parechovirus
Cardioviruses
HAV
25
Poliovirus morphology
Naked + ssRNA (icosahedral symmetry)
26
Poliovirus transmission
Oral-fecal route
27
Poliovirus pathogenesis
Replicates in motor neurons in anterior horn of spinal cord causing paralysis
28
Poliovirus spectrum of disease
Poliomyelitis
Meningitis
29
Poliovirus diagnosis
Cowdry type B
intranuclear inclusion
30
Prevention of poliovirus
Salk (IPV; killed virus)
Sabin vaccination (OPV; live attenuated virus)
31
Poliovirus inactivated when heated at
55°C for 30 minutes
32
In Poliovirus , this can prevent inctivation
Mg2+
1 mol/L
33
purified poliovirus is inactivated by a
chlorine concentration of 0.1 ppm
34
In poliovirus, higher concentrations of ___________ are required to disinfect sewage containing virus in fecal suspensions and in the presence of other organic matter.
Chlorine
35
Most strains can be grown in primary or continuous cell line cultures derived from a variety of human tissues or from monkey kidney, testis, or muscle but not from tissues of lower animals.
Poliovirus
36
Poliovirus portal of entry
Mouth
37
Poliovirus primary multiplication takes place in the
oropharynx or intestine
38
Poliovirus may be found in ________ of patients with nonparalytic poliomyelitis
blood
39
WHat virus Antibodies to the virus appear early in the disease, usually before paralysis occurs
Poliovirus
40
Coxsackie virus morphology
Naked + ssRNA icosahedral symmetry
41
Coxsackie virus ( A and B) transmission
Oral-fecal route
42
Coxsackie virus ( A and B) Spectrum of disease
Coxsackie A virus
(Herpangina, acute hemorrhagic conjunctivitis, HFMD and aseptic meningitis)
Coxsackie B virus
(Pleurodynia, severe generalized disease of infants, pericarditis and myocarditis and
aseptic meningitis)
43
is caused by all types of group B coxsackieviruses and by many group A coxsackieviruse
Aseptic meningitis
44
Aseptic meningitis most common
A7 and A9
45
A severe febrile pharyngitis that is caused by __________
Herpangina
Coxsackie A
46
Despite its name, it has nothing to do with herpesviruses
Herpangina
47
There is an abrupt onset of fever and sore throat with discrete vesicles on the posterior half of the palate, pharynx, tonsils, or tongue.
Herpangina
48
The disease sometimes progresses to mild muscle weakness suggestive of paralytic poliomyelitis.
Aseptic meningtis
49
The illness is self-limited and most frequent in small children.
Herpangina
50
also known as epidemic myalgia
Pleurodynia
51
Epidemic myalgia is caused by
Group B viruses
52
The chest pain may last from 2 days to 2 weeks. Abdominal pain occurs in approximately half of cases, and in children, this may be the chief complaint.
Pleurodynia
53
The illness is self-limited and recovery is complete, although relapses are common.
Pleurodynia
54
ECHO morphology
Naked + ssRNA
55
ECHO transmission
Oral-fecal route
56
ECHO MEANS
Enteric Cytopathic Human Orphan
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Enteric Cytopathic Human Orphan ECHO
Spectrum of disease
Aseptic meningitis, URTI, febrile illness ( with or without rash) infantile diarrhea and hemorrhagic
conjunctivitis
58
Rhinovirus morphology
Naked + ssRNA (>100 serotypes)
59
Rhinovirus transmission
Aerosol droplets and hand-to-nose contact
60
Rhinovirus pathogenesis
replicate better at 33°C than at 37°C → affect primarily the nose and conjunctiva rather
than the lower respiratory tract (acid-labile killed bygastric acid)
61
replicate better at 33°C than at 37°
Rhinovirus
62
Hepatitis A also known as
Enterovirus 72
63
Hepatitis A virus morphology
Naked + ssRNA (single serotype)
64
Hepatitis A transmission
Oral-fecal route
65
Hepatitis A pathogenesis
replicated in the GI tract and then spreads to the liver during a brief viremic period
66
Hepatitis A spectrum of disease
Hepatitis A infection
- self-limited, short incubation hepatitis and anicteric hepatitis
67
Hepatitis A diagnosis
anti-HAV IgM
68
Hepatitis A treatment and prevention
administration of immune globulin during IP and vaccination (killed virus)
69
Togaviridae
Rubella virus
70
Rubella virus morphology
enveloped, icosahedral, non-segmented (+ ssRNA) [1 serotype]
71
Rubella virus transmission
respiratory droplets and transplacental
72
Rubella virus pathogenesis
replicates in the GI tract and then spread to the liver during a brief viremic period
73
Rubella virus prevention
MMR vaccine
74
Rubella virus also known as
German measles
3-day measles
75
Incubation period of rubella virus
14-21 days
76
Rubella virus period of communicability
1 week before up to 1 week after the appearance of rash
77
malaise, fever and anorexia for several days; may be accompanied by mild coryza and conjunctivitis (children may not have a prodrome)
Rubella virus/ German measles/3-day measles
78
Cephalocaudal appearance of maculopapular rash
RUBELLA / GERMAN MEASLES / 3-DAY MEASLES
79
Most characteristic clinical feature of RUBELLA / GERMAN MEASLES / 3-DAY MEASLES
Postauricular lymphadenopathy:
80
Forchheimer's spots
RUBELLA / GERMAN MEASLES / 3-DAY MEASLES
81
(petechiae on soft palate; not pathognomonic)
Forchheimer's
82
In rubella virus it is caused by immune complexes (especially in adult women)
polyarthritis
83
Natural infection leads to lifelong immunity.
RUBELLA / GERMAN MEASLES / 3-DAY MEASLES
84
Risk is greatest early in fetal development when cell differentiation is at a peak (first trimester)
CONGENITAL RUBELLA SYNDROME
85
Rubivirus infected human embryo cells demonstrate
chromosomal breakage and inhibition of mitosis.
86
Body areas affected in congenital rubella include:
• Heart: patent ductus, interventricular septal defects, pulmonary artery stenosis, etc.
• Eye: cataracts, chorioretinitis, etc.
• CNS: mental retardation, sensorineural deafness, microcephaly
87
"blueberry muffin"
CONGENITAL RUBELLA SYNDROME
88
appearance due to dermal extramedullary hematopoiesis
"blueberry muffin" (CRS)
89
Flaviviridae
● Dengue Virus
● Hepatitis C Virus (HCV)
● Zika Virus
● Yellow Fever
● West Nile Virus
90
Dengue virus morphology
enveloped, icosahedral, non-segmented, (+ssRNA) [4 serotypes]
91
Dengue virus transmission
bite of female Aedes aegypti mosquito ( A. albopictus)
92
Dengue virus spectrum of disease
Dengue Fever (Breakbone. Fever) and Dengue
hemorrhagic fever
93
Dengue virus diagnosis
NS1 antigen
RT-PCR
Dengue IgM and IgG
CBC ( platelet count)
94
Dengue virus prevention
Insecticide, draining of stagnant water, mosquito
repellent and dengue vaccine
95
Influenza-like syndrome characterized by biphasic fever, myalgia, arthralgia, rash, leukopenia and lymphadenopathy
DENGUE FEVER (BREAKBONE FEVER)
96
severe, often fatal, febrile disease characterized by capillary permeability, abnormalities of hemostasis and a protein-losing shock syndrome
DENGUE HEMORRHAGIC FEVER
97
due to the production of large amounts of cross-reacting antibody at the time of a second dengue infection (antibody-dependent enhancement)
Hemorrhagic shock syndrome
98
Severe plasma leakage, leading to:
- Shock
- Fluid accumulation with respiratory distress
• Severe bleeding
• Severe organ impairment
Severe dengue
99
Confirmed dengue:
• Viral culture isolation
• PCR
100
Hepatitis C virus (HCV) morphology
enveloped, icosahedral, non-segmented, (+ssRNA) [ at least 6 serotypes]
101
Mojor transmission oh hepatitis C
blood-borne, IV drug users
102
Minor transmission oh hepatitis C
NSI, during birth and sexual
103
Replication of HCV in the liver is enhanced by a liver-specific microRNA
miR-122
104
acts by increasing the synthesis of HCV mRNA.
Micro-RNA
105
The death of the hepatocytes is probably
caused by
Immune attack by cytotoxic cells
106
Diagnosis HCV
anti-HCV antibodies
recombinant immunoblot assay (RIBA)
PCR ( HCV-RNA)
107
Prevention HCV
1. Acute hepatitis C: Peginterferon alfa
2. Chronic hepatitis C: combination of Peginterferon alta-za and ribavirin
if genotype 1, add: protease inhibitor (boceprevir, simeprevir)
108
Acute hepatitis C:
Peginterferon alfa
109
Chronic hepatitis C: combination
Peginterferon alta-za and ribavirin
110
greatly enhances the rate of hepatocellular carcinoma in HCV-infected individuals.
Alcoholism
111
REMINDER‼️‼️‼️
Rate of chronic carriage of HCV is much higher than that of HBV
112
HCV Incubation period
8 weeks
113
Acute infection: HCV
milder than infection with HBV
114
REMINDER‼️‼️
Hepatitis C resembles hepatitis B as far as the ensuing chronic liver disease, cirrhosis, and the predisposition to hepatocellular carcinoma are concerned
115
HCV infection also leads to significant autoimmune reactions and extrahepatic manifestations, including:
o Thyroiditis
• Autoimmune hemolytic anemia
• ITP
• MPGN
• DMI
• leukocytoclastic vasculitis
• 🔝risk of B-cell NHL
• lichen planus |
• porphyria cutanea tarda
116
main cause of essential mixed cryoglobulinemia
HCV
