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Flashcards in Herpesviruses Deck (104):
1

What are herpesviruses? 

Large enveloped dsDNA viruses 

2

How long do herpesvirus infections last? 

Lifelong

3

What is the pattern of a herpesvirus infection? 

Latency following the acute primary episodes and relapses occuring later in life when the individual becomes immunosuppressed 

4

How many types of herpesvirus are there? 

8

5

What are the classes of herpesviruses?

  • α-herpesviruses
  • ß-herpesviruses
  • γ-herpesviruses

6

What are the features of class α-herpesviruses? 

Fast growing cytolytic viruses that establish latent infection in sensory ganglia 

7

What are the α-herpesviruses? 

  • HSV1
  • HSV2
  • VZV

8

What are the features of class ß-herpesviruses? 

Slow growing viruses that lie latent in secretary glands and in the kidneys, and have long replication cyles

9

What are the ß-herpesviruses? 

  • CMV
  • HHV6
  • HHV7

10

What are the features of class γ-herpesviruses? 

Latency occurs in lymphoid tissues 

11

What are the γ-herpesviruses? 

  • EBV
  • Karposi's Sarcoma Virus 

12

What type of envelope do herpes viruses possess? 

Lipid 

13

What surface do herpes viruses prefer? 

Moist mucosal surfaces 

14

Where are herpes viruses commonly secreted? 

By oral and genital secretions 

15

What is oral transmission of the herpes virus associated with? 

Primary infection at an early age 

16

When does genital tranmission of the herpes virus cause infection? 

At a later period in life 

17

Does oral or genital transmission of the herpes virus have a higher seroprevelance? 

Oral 

18

What are herpes viruses able to do with their genetic information? 

Integrate it into host cells

19

What happens once herpes viruses' have integrated their genetic information into host cells? 

They remain as latent infections, and can occassionally reactivate their genetic material 

20

What happens once herpes viruses' have reactivated the genetic material they had previously integrated into host cells? 

  • Causes clinical illness
  • Spreads to other susceptible individuals 

21

What can some herpes viruses exhibit? 

Oncogenic potential 

22

How severe are primary infections of herpes? 

Usually mild or subclinical 

23

How severe are subsequent presentations of herpes? 

Can have the potential to cause serious life-threatening illness

24

Who is especially at risk of subsequent life threatening presentations of herpes? 

Immunosuppressed individuals 

25

What is HHV 1 known as? 

HSV1

26

What is HHV 2 known as? 

HSV2

27

How are HSV1 and HSV2 spread? 

By direct, person-to-person contact 

28

Is HSV1 or HSV2 more common from oral transmission? 

HSV1

29

Who is HSV1 common in? 

Young children 

30

What will HSV1 infection result in? 

Asymptomatic response

31

What can HSV1 cause on reactivation?

  •  'Cold sores'
  • Dendritic ulcers
  • Herpetic whitlow in traumatised skin
  •  Fatal encephalitis 

32

When does HSV1 reactivate as 'cold sores'?

In times of stress

33

What are the symptoms of fatal encephalitis? 

Personality changes and confusion 

34

What can maternal transmission of HSV1 during childbirth result in? 

Neonatal herpes 

35

Is HSV1 or HSV2 more common from genital transmission? 

Genital 

36

What does HSV1 cause? 

Genital ulceration

37

How does the recurrent infection of HSV2 differ from HSV1? 

Milder and shorter lived 

38

Why are the genital ulcers caused by HSV2 important? 

Important in the transmission of the HIV infection 

39

What class of herpesvirus are HSV1 and HSV2? 

α 

40

Where do HSV1 and HSV2 affect on initial epithelial cell infection? 

The ganglion

41

Where do HSV1 and HSV2 viruses stay latent? 

In the sensory neurone ganglion 

42

What is HSV3 known as? 

Varicella Zoster Virus (VSV)

43

How many serotypes does VSV have? 

1

44

By what route is VZV spread? 

Aerosol 

45

How is VZV spread via the aerosol route? 

The vesicles rupture to release the virus, and the VSV then spreads by aerosol spread 

46

Where does VZV remain latent? 

In the sensory ganglion

47

How does the primary infection of VZV appear? 

Chicken pox

48

What is the infection rate of chickenpox? 

90%

49

What happens in chickenpox? 

Lesions and vesicular eruptions will form, which will subsequently rupture to release the VZV into the atmosphere and will heal spontaneously 

50

What is the outcome of chickenpox? 

Complete resolution is normal, unless lesions become infected as a result 

51

What can VZV cause if its primary presentation is in adults? 

VZV pneumonia

52

Who is especially at risk of VZV pneumonia? 

Immunocompromised individuals 

53

What is the prognosis of VZV pneumonia? 

High mortality

54

What does the reactivation of VZV from the sensory root ganglion cause?

Shingles 

55

What happens in shingles? 

The virus travels down the axon of the sensory route ganglion to produce lesions in that dermatome 

56

What is shingles commonly triggered by? 

  • Stress
  • Immunocompromisation

57

What can shingles cause in the elderly? 

  • Ocular damage
  • Post hepatic neuralgia

58

When does primary infection of VZV commonly occur? 

Between 4-10 years 

59

What does primary infection of VZV provide? 

Lifelong immunity 

60

What is HHV 4 known as? 

The Epstein Barr virus (EBV)

61

What does EBV cause? 

Infectious mononucleosis 

62

What class of herpesvirus is EBV? 

γ 

63

How does EBV spread? 

Via saliva 

64

What % of the population is EBV found in? 

90-95%

65

How does EBV gain entry? 

Via the pharynx

66

What does EBV infect once it has gained entry? 

B lymphocytes 

67

What happens once EBV has infected the lymphocytes? 

It remains latent 

68

How can EBV evade immune responses? 

By inhibiting class I MHC presentation, reducing the load of class I MHC molecules by viral peptides

69

What are the symptoms of EBV infection? 

  • Malaise
  • Fever
  • Sore throat 
  • Lymphadenopathy

70

What properties does EBV have? 

Oncogenic

71

What cancers can be caused by EBV?

  • Burkitt's lymphoma
  • Nasopharyngeal carcinoma
  • Lymphoma

72

Where does EBV cause Burkitt's lymphoma? 

Sub-saharan Africa 

73

What is EBV caused Burkitt's lymphoma in association with? 

Malaria 

74

Where does EBV cause nasopharyngeal carcinoma? 

China 

75

In whom does EBV cause lymphoma? 

Immunosuppressed individuals 

76

How long do symptoms of EBV last? 

Around 2 weeks 

77

What is treatment of EBV infection based on? 

Mainly symptoms based 

78

What is HHV 5 known as? 

Cytomegalovirus (CMV)

79

How is CMV transmitted? 

  • Vertical
  • Saliva
  • Blood 
  • Sexual transmission

80

What is the prevalance of CMV?

Around 50% of the population by 35 years 

81

Where des CMV remain latent? 

In monocytes and lymphocytes 

82

What class of herpesvirus is CMV?

ß

83

What is the clinical presentation of CMV? 

Often asymptomatic or subclinical in initial infection, yet can produce mononucleosis-like symptoms in some

84

When can CMV spread to neonates? 

To the foetus before birth, or after birth 

85

What can CMV cause in neonates? 

  • Serious infections
  • Later developmental defects 

86

What can reactivation of CMV in immunocompromised individuals cause? 

  • Severe pneumoitis
  • Colitis
  • Retinitis 

87

What can retinitis develop to? 

  • Retinal detachment
  • Blindness 

88

What does CMV cause on histology? 

A 'giant owl' inclusion body 

89

By when is HHV 6 and HHV 7 found in most individuals? 

The second year of life

90

What is often the effect of HHV 6 and HHV 7 infection? 

It is often subclinical

91

How can HHV 6 and HHV 7 sometimes arise in some individuals? 

As Rosala infantatum 

92

What are the symptoms of Rosala infantatum? 

Produces rash and fever

93

What class of herpesvirus are HHV 6 and HHV 7? 

ß

94

What is HHV 8 also known as? 

Kaposi's sarcoma virus 

95

How is HHV 8 transmitted? 

Vertically, or via mucosal transmission

96

How does HHV 8 initially present? 

With mononucleosis-like symptoms 

97

In whom can HHV 8 reactivate? 

Immunocompromised individuals 

98

How does HHV 8 present on reactivation in immunocompromised individuals? 

As a vascularised tumour 

99

What causes the vascularised tumour in HHV 8 infection? 

Excessive angiogenesis, inflammation, and proliferation 

100

How can the tumour in HHV 8 infection be treated? 

Radiotherapy

101

What is a HHV 8 tumour associated with? 

HIV 

102

How is diagnosis of the herpesvirus made? 

Though NAAT using specimens ffrom rashes, blood, or urine, or through serological testing 

103

What does treatment of herpesviruses involve? 

Mainly supportive care, yet in severe cases anti-virals can be used 

104

What antivirals are used in the treatment of herpesvirsuesa? 

Mainly ganciclovir or aciclovir