Hdm Test 3: Viral Stis - Hsv

Front 1

Key difference between Herpes simplex and varicella zoster virus

Back 1

Varicella is more disseminated infection; herpes more localized

Front 2

Describe the structure of the HSV

Back 2

linear ds DNA with capsid, surrounded by tegument, which is further surrounded by a lipid envelope + glycoprotein spikes

Front 3

Alpha herpes virus

Back 3

HSV1, HSV2, Varicella-zoster

Front 4

Beta herpes virinae

Back 4

CMV and HHV6b (slapped cheek disease)

Front 5

Gamma herpes virus

Back 5

Kaposi's sarcoma herpes and Epstein-Barr virus

Front 6

General concepts about alpha-herpes viruses

Back 6

-acute primary infection (neonates susceptible to sepsis-like)
-latency (like DRG and trigeminal ganglion)
-Disease from reactivation from latency
-Primary and reactivated more severe with immunosuppressed individuals

Front 7

Mechanisms of pathogenesis for alpha-herpes

Back 7

-cell killing from virus replication
-sepsis, systemic inflammatory response
-immune-mediated disease (corneal scarring)

Front 8

Epidemiology for alpha-herpes virus

Back 8

-no seasonal occurrence
-vast occur by adolescence
-Transmission by respiratory (VZV); saliva, lesion contact or sexual activity (HSV1 and HSV2)
-Spread of HSV-1 helped by high incidence of asymptomatic shedding

Front 9

Differences between HSV-1 and HSV-2

Back 9

HSV1 in orofacial, HSV2 in genitals
75% are HSV-1 seropositive, 25% HSV-2

Front 10

Herpes replication cycle initial replication found where?

Back 10

-nucleated cells of mucosal epithelium of oropharynx or genitals
-follows breaks in keratinized epithelium in cells of basal epithelium

Front 11

How do HSV enter on a cellular level?

Back 11

Surface fusion or receptor-mediated endocytosis
-then spreads to sensory neurons for HSV/VZV

Front 12

Where does HSV transcription and replication occur?

Back 12

nucleus

Front 13

How does herpes virus leave the nucleus?

Back 13

Into ER (gains and loses envelope)

Front 14

Where does HSV latency principally occur?

Back 14

trigeminal ganglion, sacral ganglia, or DRGs and TG

Front 15

What occurs with the viral DNA when the virus reaches the neuronal cell bodies?

Back 15

limited replication, stable circular episome

-basically doesn't appear

Front 16

What triggers reactivation of herpes virus?

Back 16

Who knows

Front 17

Worst case retrograde spread of HSV can lead to...

Back 17

encephalitis

Front 18

Factors involved in maintenance of neuronal HSV latency

Back 18

epigenetic silencing
CD8+ T cells in vicinity
Viral non-coding RNAs that don't encode proteins (suppress expression of regulatory proteins)

Front 19

3 types of primary acute infection of HSV-1

Back 19

gingivostomatitis (sores of tongue/lips/buccal mucosa/palates)
pharyngitis w/ flu-like symptoms
keratoconjunctivitis and genital infection less frequent
(resolve within 1-2 weeks)

Front 20

Herpetic whitlow is caused by what?

Back 20

HSV-1 (direct inoculation)

Front 21

Herpes gladiatorum is caused by what?

Back 21

something like wrestling, HSV-1

Front 22

Primary infection of HSV-2

Back 22

genital sores
flu-like symptoms
(latent infection in sacral ganglia)

Front 23

Responses to acute HSV infection

Back 23

Epigenetic silencing
Interferon (type I)
PKR (stops eIF2alpha to inhibit protein synthesis)
Proinflammatory cytokines

Front 24

Evasion of intrinsic responses to HSV infection

Back 24

acetylation (in response to epigenetics)
Inhibits IFN transcription
Inhibits PKR

Front 25

Immune responses to HSV infection

Back 25

IFN expression, presentation of viral peptides (MHC I)
-recruit naive CD8+ and CD4+
Phagocytosis by immature monocytes
-secrete IL12, bring in NK cells
Infect monocytes

Front 26

Reactivated herpes generally presents as...

Back 26

cold sores

Front 27

Dx of herpes

Back 27

pathognomonic lesions-multiple vesicular lesions on red base
Isolation from clinical material-development of cytopathic effect
Serology-use ELISA to distinguish between HSV-1 and -2
Can also see multinucleated cells fused together

Front 28

Wright-Giemsa stain is used for what?

Back 28

cytopathic effect in herpes virus

Front 29

Presentation of varicella

Back 29

mild systemic febrile illness
incubation of 21 days
transmission by respiratory droplets or direct contact

Front 30

Dissemination of varicella zoster

Back 30

Initial replication in respiratory epithelium
Viremia spreads to liver and spleen
Secondary viremia transports virus to skin and repiratory mucosal sites

Front 31

Secondary complications for varicella zoster

Back 31

secondary bacterial infections

Front 32

what is reactivated zoster linked to?

Back 32

dermatomes (DRG)

Front 33

Most frequent complication to shingles

Back 33

Post herpetic neuralgia

Front 34

tx of varicella zoster

Back 34

acyclovir (similar to guanosine)
pro-drug

Front 35

What enzyme IDs acyclovir in viruses?

Back 35

thymidine kinase (incorporated into viral DNA, stopping replication)

Front 36

Which population is more susceptible to acyclovir resistance?

Back 36

Immunocompromised

Front 37

Most common mechanism for resistance to nucleoside analogs?

Back 37

reduced levels of thymidine kinase