Herpesviruses

Question 1

All herpes infections begin with ___________.

Answer 1

primary infection

Question 2

After primary infection, herpes viruses can do one of two things: _____________.

Answer 2

lytic replication or latency

Question 3

Lytic replication can manifest as _____________.

Answer 3

disease or asymptomatic shedding

Question 4

What structure do herpes viruses (all of them) have?

Answer 4

Enveloped dsDNA with outer glycoproteins that allow infection

Question 5

Herpes viruses can present with _____________ inclusions.

Answer 5

nuclear and cytoplasmic

Question 6

Briefly describe the three subgroups of herpes viruses.

Answer 6

Alpha: establish latent infections in neurons (HSV1, HSV2, and VZV)

Beta: establish latent infections in myeloid cells (CMV, HH6, and HHV7)

Gamma: establish latent infections in B cells and myeloid cells (EBV, KSV)

Question 7

What shape does the herpes capsid have?

Answer 7

It is icosahedral.

Question 8

The viral capsid is ______ to the envelope.

Answer 8

deep

Question 9

The fastest herpes virus subgroup (that is, fastest to develop) is ______________.

Answer 9

alpha (12 - 24 hours)

Question 10

Alpha herpes viruses (HSV1, HSV2, and VZV) reside in _____________ neurons.

Answer 10

sensory ganglia

Question 11

What part of the virus stimulates adaptive immunity?

Answer 11

The envelope glycoprotein

Question 12

_________ is the only herpes virus to be transmitted via respiratory secretions.

Answer 12

VZV

Question 13

Herpes viruses transcribe proteins in three stages: _______________.

Answer 13

• Immediate early: proteins that help create a favorable intracellular environment
• Early: proteins needed for replication (e.g., viral DNA polymerase)
• Late: structural proteins

Question 14

What mechanism allows for very fast replication of viral genomes?

Answer 14

Rolling circle replication –a process like unraveling toilet paper

Question 15

Acyclovir requires ___________ to become active.

Answer 15

thymidine kinase (as such, organisms such as beta herpes viruses – like CMV – that do not use thymidine kinase are resistant to acyclovir)

Question 16

Ganciclovir requires _______ to become active.

Answer 16

UL97

Question 17

Why are cidofovir and foscarnet more toxic?

Answer 17

They are activated by cellular kinases and thus inhibit host DNA as well.

Question 18

True or false: the viral envelope comes from the nuclear envelope.

Answer 18

False. Viruses do acquire an envelope at the nucleus, but they lose it and regain another in the Golgi.

Question 19

What is the difference between Cowdry bodies and CMV inclusions?

Answer 19

Cowdry bodies are eosinophilic – pink –and CMV bodies are basophilic.

Question 20

HSV1 is typically latent in _______________, while HSV2 is typically latent in ______________.

Answer 20

the trigeminal ganglion; the sacral ganglia

There are, of course, exceptions.

Question 21

Once an HSV lesion ____________, it is no longer infectious.

Answer 21

scabs over

Question 22

By age 50, ________ percent of people are seropositive for HSV1.

Answer 22

90

Question 23

Severe primary infection with HSV or immuno- compromisation can lead to a painful oral symptom: _____________

Answer 23

gingivostomatitis (swelling of the gingiva)

Question 24

Because of ______________, secondary HSV is not as severe –often presenting with cancre sores.

Answer 24

T-cell memory

Question 25

A patient presents with _____________ and you say "I know, they have herpetic encephalitis!"

Answer 25

fever, confusion, focal neurologic findings, and mononuclear cells in their CSF

Question 26

HSV2 often presents with ___________ superinfection.

Answer 26

candida

Question 27

Explain the clinical terminology for VZV.

Answer 27

Primary: chickenpox Reactivation: zoster

Question 28

Where does primary VZV replicate?

Answer 28

In lymph nodes

Question 29

What is the classic description of primary VZV infection?

Answer 29

Crops of vesicles of varying age

Question 30

What are some complications of VZV?

Answer 30

- Bacterial superinfection (most common problem) - Severe adult infection (including pneumonia and sepsis) - Encephalitis - Congenital

Question 31

What is Hutchinson sign?

Answer 31

Reactivation of VZV in the V1 dermatome of the face that leads down to the tip of the nose Note: if you see this, consult an ophthalmologist because the V1 also enters the eye.

Question 32

How can shingles be treated?

Answer 32

Acyclovir is effective if given in the first 3 or 4 days of symptoms.

Question 33

What complications can result from shingles?

Answer 33

- Motor deficits - Encephalitis - Eye involvement - Post-herpetic neuralgia

Question 34

Part of why the elderly are at increased risk of shingles is ____________.

Answer 34

decreased T-cell immunity

Question 35

The shingles vaccine is recommended for those ___________.

Answer 35

60 and older

Question 36

Beta herpesviruses infect _________-positive cells.

Answer 36

CD34 (hematopoietic stem cells)

Question 37

Most neonatal CMV results from __________.

Answer 37

breast milk

Question 38

CMV in adolescents can cause ______________.

Answer 38

a mononucleosis-type syndrome

Question 39

How should CMV be treated?

Answer 39

With ganciclovir or foscarnet (if the virus has UL97 mutations)

Question 40

The "slapped-cheek" disease is caused by __________ and has two names: ____________.

Answer 40

parvovirus B19; 5th disease and erythema infectiosum

Question 41

A mother tells you her child had a fever yesterday and a rash today. What virus is this? What is the most common pattern of virus?

Answer 41

Roseola; a maculopapular rash that starts on the trunk and moves to the face

Question 42

The most important gamma herpesvirus is _____________.

Answer 42

EBV

Question 43

What do EBVNA1 and EBVNA2 do?

Answer 43

EBVNA1: links EBV DNA to host genome EBVNA2: activates viral genes and c-myc (hence Burkitt)

Question 44

What is the pathogenesis of EBV?

Answer 44

B cells get infected in the tonsils and spread throughout the body. T cells kill the B cells, and the inflammation from that causes systemic symptoms.

Question 45

Why do heterophile antibodies develop from EBV infection?

Answer 45

EBV stimulates B cells to proliferate regardless of antigen presentation. As such, the blood of someone actively infected with EBV will display agglutination to random antigens.

Question 46

How sensitive is the monospot test?

Answer 46

~85%

Question 47

What virus causes Kaposi's sarcoma?

Answer 47

HHV8 (gamma herpes virus)

Question 48

The virus that causes Kaposi's sarcoma resides latent in ________________.

Answer 48

B cells

Question 49

Why do herpesviruses typically require close contact?

Answer 49

Because they are easily killed in the environment

Question 50

The envelope around herpesviruses (all of them) is derived from _____________.

Answer 50

the host cell's Golgi apparatus

Question 51

When the rash from a herpesvirus has __________, it is usually not contagious anymore.

Answer 51

crusted over

Question 52

True or false: primary herpes infections are most often asymptomatic.

Answer 52

True. Only about 20% of cases present with symptoms.

Question 53

Even people without herpes symptoms can ______________.

Answer 53

spread the virus to others

Question 54

A classic finding of CMV infection in an adult is ______________.

Answer 54

interstitial pneumonia | Remember the lung stains on the butcher's apron.

Question 55

The acute test for EBV tests ________, while _________ will appear after an infection.

Answer 55

IgM; IgG

Question 56

It takes about __________ days for VZV to present as chickenpox.

Answer 56

10-20

Question 57

The two most common congenital herpes infections are ___________________.

Answer 57

CMV (40,000 per year) and HSV (1,200 per year)