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Flashcards in Major RNA viruses Deck (128)
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1
Q

What are the components of a naked virus?

A

Capsid and nucleic acid

2
Q

What are the components of an enveloped virus?

A

Envelope of glycoproteins
Spikes
Capsid
Nucleic acid

3
Q

How are capsids symmetrical?

A

Identical proteins “capsomeres”

Based on icosahedral or helical structure

4
Q

What is the purpose of the capsid?

A

Protects the genetic material

Recognized when its attached to the host

5
Q

What RNA viruses are +ssRNA, enveloped and icosahedral?

A

Flavivirdae
Togaviridae
Retroviridae

6
Q

What RNA virus is +ssRNA, enveloped and helical?

A

Coronaviridae

7
Q

What RNA viruses are +ssRNA, nonenveloped and icosahedral?

A

Picornvaviridae

Caliciviridae

8
Q

What RNA viruses -ssRNA, enveloped and helical?

A
Orthomyxoviridae
Paramyxoviridae
Rhabdoviridae
Filoviridae
Bunyaviridae
Arenaviridae
9
Q

What RNA viruses are dsDNA, nonenveloped and icosahedral?

A

Reoviridiae

10
Q

All RNA viruses replicate in the cytoplasm except;

A

Orthomyxoviridae and Retroviridae

11
Q

All RNA viruses are single stranded except:

A

Reoviridae

12
Q

All RNA viruses and evveloped except;

A

Picornaviridae
Caliciviviridae
Reoviridae

13
Q

All -ssRNA viruses are ___ in shape.

A

Helical

14
Q

Why do RNA viruses have a high rate of mutation?

A

Because they lack DNA polymerase

15
Q

What are the three genus classifications for Picornaviruses?

A

Enterovirus
Rhinovirus
Hepatovirus

16
Q

What are the species within enterovirus?

A
Poliovirus 1-3
Echovirus 1-34
Coxsackievirus A 1-24
Coxsackievirus B 1-6
Enterovirus 68-71
17
Q

What is the species within Rhinovirus?

A

Human Rhinovirus 1-115

18
Q

What is the species within Hepatovirus?

A

Hepatitis A virus

19
Q

What are some characteristics of Picornavirus?

A

Small is large
Large family
Replicate in cytoplasm
Non-enveloped, +sslinear, icosahedral

20
Q

What are the only susceptible host for poliovirus?

A

Humans

21
Q

The 3 serotypes of polio have ___ homology.

A

33-66%

22
Q

What are the two vaccine types for polio?

A

IVP (Salk) inactive

OPV (Sabin)

23
Q

Who many infections of polio are type 1?

A

70 - 90%

24
Q

How is polio transmitted?

A

Ingestion (fecal-oral)

25
Q

Where does polio infect once in the body?

A

Cells of the oropharyngeal and intestinal mucosa

26
Q

Where does polio replicate?

A

In the lymph nodes and GALT

27
Q

Which is more common, a primary or secondary viremia of polio?

A

Primary (95%)

28
Q

How many cases of polio spread to the CNS?

A

1%

29
Q

Where is polio spread?

A

Feces

30
Q

What are the clinical manifestations of polio?

A

Meningitis (aseptic)
Encephalitis
Paralytic poliomyelitis

31
Q

If polio has attacked the anterior horn of of the spinal cord what happens?

A

Flaccid paralysis

32
Q

What happens if polio attacks the medulla?

A

Paralysis of the diaphragm - you ded

33
Q

What viruses are a common cause of lymphocytic meningitis?

A
Enterovirus
Coxsackie virus A & B
Echovirus
Poliovirus
Arbovirus
HIV
HSV-2
34
Q

What are the three types of paralytic polio?

A

Spinal (80%)
Bulbar (2%) muscle weakness
Bulbospinal (15%) combo of both

35
Q

How is polio diagnosed?

A

Isolation of virus from stool or CSF

36
Q

How is polio treated?

A

No specific treatment

  • pain and muscle spasm treatment
  • orthopedic support
37
Q

Which of the polio vaccines were effective against all 3 strands?

A

Both Salk and Sabin

38
Q

What are the good things about OPV for polio?

A

Oral
Lifelong immunity
No boosters needed
Contributes to herd immunity

39
Q

What are the bad things about OPV for polio?

A

Risk of vaccine associated polio

Immunocompromised can’t have it

40
Q

What are the good things about IPV for polio?

A

No risk of vaccine associated polio
Safe for immmunocompromised
Easier to store and transport

41
Q

What are bad things about IPV for polio?

A

Booster needed
Injection
Large dose needed

42
Q

How is Coxsackievirus transmitted?

A

Ingestions (fecal-oral) and highly contagious

43
Q

What is the vaccine for coxsackie?

A

None

44
Q

What is the treatment for coxsackie?

A

None

just wash your hands and don’t get it

45
Q

What coxsackie virus type causes hand, foot and mouth disease and what are the symptoms?

A

A9, A16

Vascular rash on hands, feet, mouth and tongue with mild fever

46
Q

What coxsackie virus type causes hemorrhagic conjuctivitis and what are the symptoms?

A

A24
Eye pain followed by redness, tears, swelling and sensitivity
Contagious

47
Q

What coxsackie virus type causes poliomyelitis like symptoms?

A

A7

48
Q

What other diseases do coxsackie A virus cause?

A

Aseptic meningitis

Herpangina

49
Q

What are the characteristics of coxsackie B?

A

Worldwide distribution

All but one type found in the US first

50
Q

What coxsackie virus type B might be associated with hand, foot and mouth disease?

A

B2 and B5

51
Q

What coxsackie virus type cases juvenile diabetes (IDDM)?

A

B4

52
Q

What other diseases does coxsackie type B cause?

A

Pleurodynia

Myocarditis

53
Q

What are the symptoms for herpangina?

A

Fever, sore throat, anorexia, vomiting

Vesicular ulcerating lesions on soft palate and uvula

54
Q

What are the symptoms for pleurodynia?

A

Acute onset of fever, unilateral low thoracic chest pain
Pain is called “devil’s grip”
Males have testicular pain

55
Q

Describe the characteristics of Rhinovirus.

A

Most common cause of the common cold
More common in the summer
Infection localized in the nose

56
Q

How is rhinovirus transmitted?

A

Respiratory secretions

57
Q

What are the symptoms of rhinovirus?

A

Runny nose

58
Q

What is the treatment for rhinovirus?

A

None

59
Q

What was Hepatitis A originally known as?

A

Enterovirus 72

60
Q

How is Hep A transmitted?

A

Fecal-Oral

61
Q

What are the symptoms of Hep A?

A

Sudden fever and jaundice

62
Q

What does Hep A infect?

A

Intestinal epithelial cells and spread to liver

63
Q

What causes the life long immunity to Hep A?

A

IgG anti hep A

64
Q

What is the treatment for Hep A?

A

None

65
Q

What are the characteristics of caliciviridae?

A

Naked, Icosahedral +ssRNA

Resistant to heat and detergent but not pH

66
Q

What is Norovirus associated with in terms of transmission?

A

Contaminated water and food supply due to fecal oral transmission

67
Q

What kind of places would you expect to see norovirus?

A

Potlucks and cruise ships

68
Q

Is norovirus highly contagious?

A

Yes

69
Q

How do you isolate norovirus?

A

The the stool or vomit of infected pts

70
Q

What does norovirus cause?

A

Acute gastroenteritis 12 0 24 hours after ingesting infected substance
Self-limits after 1 or 2 weeks

71
Q

How can you prevent norovirus?

A

Good hygiene

72
Q

How is Hepatitis E virus transmitted?

A

Fecal-oral

73
Q

What is hep E associate with in terms of transmission?

A

Contaminated water and epidemic hepatitis

74
Q

What happens if a pregnant woman get hep E?

A

She has a high chance of dying or will have a spontaneous abortion

75
Q

Reovirus is very diverse. What can it infect?

A

Mammals, birds, fish, reptiles, amphibians and plants

76
Q

What does the REO stand for in reovirus?

A

Respiratory Enteric Orphan virus

77
Q

What are the two forms of reovirus humans are mostly infected with?

A

Rotavirus

Orbivirus (coltivirus?)

78
Q

How is rotavirus transmitted?

A

Ingestion, fecal to oral

79
Q

How many children have rotovirus antibodies?

A

Almost all of them all over the world

80
Q

What is the most common cause of death due to infantile diarrhea?

A

Rotovirus

81
Q

When does rotovirus generally occur during the year?

A

Winter

Year round in the tropics

82
Q

How many type of rotovirus are there and which is the most commmon?

A

A, B, C, D, E

A is most common

83
Q

What does rotovirus type A cause?

A

Infantile diarrhea with vomiting and fever

84
Q

What does rotovirus type B cause?

A

Adult onset of severe diarrhea (epidemic in east Asia)

85
Q

What are the three major type of flavivirdae?

A

Pestivirus
Hepatitis C virus
Flavivirus

86
Q

What are the viruses within flavivirus?

A
Yellow fever
Japanese encephalitis
St. Louis encephalitis
West Nile encephalitis
Dengue
87
Q

How can you classify dengue?

A

Enveloped, +ssRNA

88
Q

What serotypes exists for denge?

A

DENV-1, 2, 3, 4

89
Q

How is denge transmitted?

A

Aedes aegypti (mosquito)

90
Q

What are the typical uncomplicated (classic) symptoms of dengue?

A
Fever within 4-7 days exposure 
Severe headache
Severe joint and muscle pain
Nausea and vomiting 
Rash
91
Q

What are the symptoms of hemorrhagic fever in dengue?

A
Symptoms of classic 
Gingival and nasal bleeding
Inc menstrual flow
GI bleeding
Hematuria
92
Q

How do you diagnose dengue?

A

ELISA serology and antigens

Tourniquet test

93
Q

How is dengue managed?

A

Self-limiting fever control (avoid aspirin)
Insect repellent
No antiviral treatment
No vaccine

94
Q

What virus is a common form of blood-borne hepatitis is hospitals?

A

Hepatitis C

95
Q

What does it mean when Hep C is in the chronic state?

A

Cirrhosis
End-stage liver disease
Hepatocellular carcinoma

96
Q

What is the main symptom of Hep C?

A

Jaundice

97
Q

What is the treatment for Hep C?

A

Pergylated IFNalpha with ribavirin

98
Q

What are the who types of togaviridae?

A

Rubivirus and Alphavirus

99
Q

What type of togaviridae is rubella?

A

Rubivirus

100
Q

What are the different type of alphavirus?

A

Chikungunya
Eastern equine encephalitis virus
Western equine encephalitis virus
Venezuelan equine encephalitis virus

101
Q

How is rubella transmitted?

A

Respiratory droplets

102
Q

How is rubella general transmitted?

A

Maculopapular rash that starts on the face and spreaks to trunk then extremities
May have occipital and post auricular lymphadenopathy

103
Q

Why is rubella dangerous if a pregnant mother contracts it?

A

It can cross the placenta is viremic and all germ layers may be infected
The early in the pregnancy the more dangerous it is, vaccine cannot be given

104
Q

What viruses are included in filoviridae?

A

Ebola
Marburg
Cuevavirus

105
Q

What symptom is associated with the viruses in filoviridae?

A

Hemorrhagic fever
Early: muscle aches, fever, vomiting, red eyes, skin rash
Acute: bleeding and skin hemorrhage

106
Q

What is the treatment and vaccine for filoviridae?

A

None

107
Q

How is orthomyxoviridae characterized?

A

Enveloped, -ssRNA, segmented

108
Q

What are the three types of orthomyxoviridae?

A

Influenza A, B and C

109
Q

Which influenza type infects humans only?

A

B

all can infect but B is exclusive

110
Q

What is antigenic drift?

A

Small, constant point mutations
Gradual changes to amino acid composition
Leads to epidemics
Annual vaccinations

111
Q

Which types of flu participate in antigenic drift?

A

A, B, C

112
Q

What is antigenic shift?

A

Substitution of a gene segment with segments from another flu virus from a different host = reassortment
Pandemics
Less common

113
Q

Which type of flu participates in antigenic shift?

A

A

114
Q

How do you name a type of influenza?

A

Host origin, geographic location of first encounter, strain number and isolation year
ex. A/California/7/2009 (H1N1)

115
Q

How is influenza transmitted?

A

Person to person, direct contact and aerosol droplets

116
Q

What does influenza infect in the body?

A

Respiratory epithelial cells

117
Q

How long does the flu incubate?

A

1 to 4 days

118
Q

What are some complications of the flu?

A

Bronchitis and pneumonia

119
Q

What treatments are there for the flu?

A

Amantidine (no longer affective)
Zanamivir (Relenza)
Oseltamivir (Tamiflu)

120
Q

What type of virus in rubulavirus and what does it cause?

A

Paramyxoviridae, mumps

121
Q

What are the structural components of a paramyxoviridae?

A
Surface G protein
Fusion protein
Matrix protein
Phosphoprotein 
Nucleoprotein
Polymerase
122
Q

What acute viral illness does the mumps cause?

A

Parotitis and orchitis

123
Q

How are the mumps transmitted?

A

Respiratory

124
Q

What is the incubation period for he mumps? when is it viremic?

A

14 - 18 days

12 - 25 days

125
Q

What are the symptoms of the mumps?

A

Nonspecific, myalgia, headache

Parotitis (30-40%)

126
Q

What type of paramyxoviridae causes the measles?

A

Morbilivirus

127
Q

What are the clinical signs of the measles?

A

Cough, coryza, conjuctivits
Koplic spots
Maculopapular rash

128
Q

What type of paramyxoviridae causes respiratory syncytial virus?

A

Pneumovirus