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Flashcards in Herpes Deck (85)
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1
Q

What are the eight impurtant human pathogens in herpeviridae

A
HSV-1
HSV-2
VZV
*alpha-short replicative cycle, broad host range
HSV-6
HSV-7
CMV
*beta- long replicative cycle, restricted host range
HSV-8 (Kaposi's sarcoma-associated HV)
EBV
*gamma- very restricted host range
2
Q

Well-known manifestation of herpes virus

A

Vesicular and pustules formation on skin

3
Q

Mode of infx of herpesvirus

A

Latent or lytic

4
Q

Long genome of herpes virus encodes for enzymes for

A

Metabolism of nucleic acid
DNA synthesis
Processing proteins

5
Q

The viral genome synthesis and capsid assembly occurs in

A

Nucleus

6
Q

Productive viral infection means

A

Inevitable cell destruction

7
Q

Four layers of the herpesvirus

A

Envelope (glycoproteins and altered host membrane)
Tegument (protein coat with viral enzymes)
Icosahedral capsid (160 capsomeres)
DNA core (double stranded)

8
Q

Its envelope protein encodes for 11 glycoproteins

A

Human simplex virus

9
Q

Binds with glycosaminoglycans

A

gB

10
Q

Interacts with GAG heparan sulfate of the target cell

A

gC

11
Q

Responsible for stability during entry fusion (HVEM host cell receptor) and elicits production of neutralizing antibodies

A

gD

12
Q

Interacts with the Fc receptor of IgG

A

gE

13
Q

Type-specific and allows antigenic discrimination between HSV-1 (gG-1) and HSV-2 (gG-2)

A

gG

14
Q

Complexes with gE and interacts with the cell junction to spread the virus from cell to cell

A

gI

15
Q

For virus capsid development (encoded by HSV)

A

gK

16
Q

Important for the viral cell entry

A

gH-gL complex

17
Q

Interaction with cell junctions to facilitate cell-cell spread (same function with gI)

A

gM

18
Q

What accounts for the low immunity to HSV?

A

Virus defense mech: Virus attaches to fc receptor of IgG to neutralize antibods

19
Q

The virus is transmitted through close contact bcos

A

It is found in semen, saliva, fluid in female genital tract, fluid in lesions

20
Q

T or F: hsv can be harbored in monkeys

A

False??- no known animal vectors

21
Q

Host cell receptors for HSV entry

A
Heparan sulfate (HSV1 only)
-GAG
Herpes virus entry mediator (HSV 1 and 2)
-member of TNF
Nectin 1 (HSV 1 and 2)
Nectin 2(HSV 2 only)
-members of Ig family
22
Q

HSV exit

A

Budding via cytloytic mech.

23
Q

Phases of replication of HSV

A

Immediate early- viral protein steps
Early- transcription of alpha genes via DNA dependent RNA polymerase II (product- posthoc phospoprotein)
Middle- transcription of beta genes (prod- DNA dependent DNA polymerase)
Late- gamma genes (most r structural proteins)

24
Q

Where does HSV usually exist in a nucleus during latency

A

Episome

25
Q

Target of HSV, presents virus to b and t cells

A

Langerhans cells

26
Q

Both cmi and HMI are triggered by hsv

A

Trohth

27
Q

Phase of latent infection of hsv going to sensory neuron to stay for years (establishment)

A

Retrograde transport

28
Q

Phase of latent infection of hsv moving out to peripheral nerve to form viruses and infect healthy cells (reactivation)

A

Anterograde transport

29
Q

HSV-1: _______::HSV-2: ________ ganglia

A

Trigeminal, lumbosacral

30
Q

Tyoe of HSV more associated with orofacial lesions, fever and blisters, encephalitis

A

HSV-1

31
Q

Type of HSV which is sexually transmitted, causes genital lesions and meningitis

A

HSV-2

32
Q

Distinguishing feature of HSV

A

blisters in genital area, rectum, mouth

33
Q

Why must hsv isolation be carried out immediately

A

Virus is labile

34
Q

Smear used for presumptive id of HSV using cell scrapings of the lesions

A

Tzanck smear

35
Q

Found in tzanck smear of cell scrapings/lesions

A

Multinucleated giant cells/syncytia
Ballooning cytoplasm
Cowdry type A intranuclear inclusion
Big nuclear body surrounded by a white halo

36
Q

Innate immune receptors sre stimulated by ________ to induce prod of type 1 IFN

A

TLR (2: viral glycoprotein and 9: Viral DNA)

37
Q

Group where varicella zoster virus is in

A

Human Alpha herpesviruses

38
Q

VZV transmission

A

Direct contact and airborne

39
Q

When is the VZV infected person contagious?

A

1-2 days before rash onset

40
Q

AEROSOL SIZE OF VZV

A

0.5-30 micrometers diameter

41
Q

Target of VZV

A

upper respiratory mucosa and conjunctiva

42
Q

Primary viremia of VZV happens in

A

Liver and spleen

43
Q

Secondary viremia happens in

A

Infected mononuclear cells

44
Q

Where does primary replication of vzv happen

A

Regional lymph nodes and lymphoreticular tissues

45
Q

Common complication of VZV

A

Postherpetic neuralgia/ZAP

46
Q

Most common site of original varicella lesions

A

Thoracic dermatome

47
Q

Varicella vesicles exhibit

A

Centripetal distribution. Lesions form crop become pustules, break down and scab over

48
Q

T or F: VZV is more severe in children

A

False

49
Q

Flared up varicella in vaccinated

A

Breakthrough varicella

50
Q

T or F: rashes in varicella in vaccinated is more vesicular than maculopapular

A

False, maculopapular than vesicular

51
Q

Common symptoms of herpes zoster/shingles

A

Headache, photophobia, malaise, fever, abnormal skin sensations and pain

52
Q

Describe herpes zoster rash

A

Unilateral, involves 1-3 dermatomes, rash is erythematous then maculopapular.

**zoster sine herpetes- no rash forms

53
Q

Specimens used for diagnosis of VZV

A

Swabs from vesicles
Skin lesion scrapings
Vesicle fluid

54
Q

What does a positive IgM ELISA mean for VZV?

A

primary VZV infection, re-infection, or re-activation

55
Q

Why is it difficult to detect increase in IgG for HZ?

A

patients may have a high baseline antibody titer from prior varicella disease

*IgG detects previous VZV infection

56
Q

What is a disadvantage of electron microscopy as diagnosis?

A

Cannit differentiate fromother herpes virus

57
Q

Purpose of laboratory diagnosis for vzv

A
  • confirm clinical diagnosis
  • determine susceptibility
  • determine if wild type or vaccine strain
58
Q

T or F: HMI is primarily involved in vzv immunity

A

False, CMI and interferon

59
Q

Varicella vaccines

A

Varivax*
Proquad*
-MMRV
Post exposure Prophylaxis
-use in healthy persons wo evidence of immunity within 3-5 days after exposure to varicella
-VARIZIG (certain groups at high risk for severe disease after exposure to VZV and within 10 days of exposure)

**LAV

60
Q

Herpes zoster vaccines

A

Live attenuated vzv- subcutaneous admin. 14x more potent
Zostavax

**no for >60 yo with varicella vax and immunocompromised

61
Q

High titer of antibody to virus, orevents varicella in immunocompromsied and infants

A

Varicella zoster immune globulin

62
Q

Major target of EBV and main reservoir of latency

A

B lymphocytes

63
Q

Infected by EBV

A

Oral epithelial cells

64
Q

Epstein barr virus primarily causes this

A

Acute Infectious mononucleosis

65
Q

It binds to MHC II on B cell membrane surface

A

Gp42

66
Q

Binds to cd21/cr2

A

Gp350

67
Q

Entry of EBV

A

Endocytosis

68
Q

Ampicillin rash is senn in this stage of infection of EBV

A

Primary stage

69
Q

Triad of symptoms of EBV

A

Fatigue, swollen lymph nodes, pharyngitis

70
Q

Kissing disease which is marked by extreme fatigue, fever, sore throat, head and body aches, swollen lymph nodes in the neck and armpits, swollen liver or spleen or both, rash

A

Infectious mononucleosis (polyclonal stimulation of lymphocytes)

71
Q

Four determinants of EBV in blood test

A

Viral capsid antigen (VCA-IgM): first to appear
VCA-IgG: second to appear, remains during convalescence
D early antigen (EA-D)
Epstein Barr nuclear antigen (EBNA)

72
Q

Seen in bloow work up of EBV infected patient

A

Increasd wbc, abnormal liver, low neutrophils and platelets

73
Q

indiccator of active infection

A

VCA-IgM

74
Q

Positive EAD

A

indicates past and current infection

75
Q

Indicative of any EBV infection

A

VCA-IgG

76
Q

EBNA is only positive for

A

Reactivation of virus and past infection

77
Q

Other complications of EBV

A

Lymphoproliferation
B cell hyperplasia
Nasopharyngeal carcinoma
Burkitt lymphoma (viral DNA is incorporated)

78
Q

Double stranded DNA
largest genome in herpes group
Has cytoplasmic inclusion bodies and induction of giant cells

A

Cytomegalovirus

79
Q

Hearing loss, vision loss, hepatitis, mononucleosis

A

Cytomegalovirus

80
Q

3 clinical syndromes of CMV

A
  • congenital CMV
  • mononucleosis
  • immunocompromised host
81
Q

Lab diag of CMV

A

Blood test

**babies:2-3 wks after infx

82
Q

Exanthem subitem (roseola) and rejection of transplanted kidneys

A

HSV 6 and 7

83
Q

Kaposis sarcoma in AIDS patients and intraabdominal tumors

A

HSV8

84
Q

Encephalitis, brain damage in survivors, bites of rhesus monkeys

A

B virus

85
Q

Taxonomy of herpes viruses

A
Lymphocryptovirus: EBV
Varicellovirus: VZV
Simplex virus: HSV1 and 2
Rhadinovirus: HSV8
Roseolovirus: HSV 6 and 7