Varicella zoster virus (chicken pox) (VIRAL)

Question 1

Varicella zoster virus is a dsDNA virus with a protective capsid and is one of the herpesviruses. It causes which 2 of the following diseases?

1 - varicella (chickenpox)
2 - herpes zoster (shingles)
3 - herpes simplex virus-1
4 - herpes simplex virus-2

Answer 1

1 - varicella (chickenpox)
2 - herpes zoster (shingles)

Question 2

Which age group is most commonly affected by VZV?

1 - 1- 5
2 - 6-15
3 - 16-21
4 - 21-35

Answer 2

2 - 6-15

Question 3

What is the annual incidence of VZV?

1 - 50 : 100,000
2 - 500 : 100,000
3 - 5000 : 100,000
4 - 50,000 : 100,000

Answer 3

2 - 500 : 100,000
- affects boys and girls equally

Question 4

Varicella zoster virus is very contagious. Typically, how is Varicella zoster virus spread?

1 - oral secretions
2 - direct skin to skin contact
3 - respiratory route
4 - genital route

Answer 4

3 - respiratory route (via droplets_
- can also be spread via skin to skin contact with the skin lesions of infected patient

Question 5

Once a patient has been infected with varicella zoster virus, which is typically in the lungs, where does the virus then move to?

1 - neuronal cell bodies
2 - lymph nodes
3 - circulation
4 - spleen

Answer 5

2 - lymph nodes
- transported here by immune cells

Question 6

Once varicella zoster virus makes its way to the lymph nodes via the immune cells, this is called primary infection. Does this cause varicella (chickenpox) or shingles?

Answer 6

• varicella (chickenpox)

There are 2 stages:
- primary viremia
- secondary viremia

Question 7

In primary viremia, varicella zoster virus infects the liver and spleen, called the reticuloendothelial system which is composed of phagocytic cells. How long before varicella zoster virus begins infecting immune cells?

1 - 2 days
2 - 1 week
3 - 2 weeks
4 - 4 weeks

Answer 7

3 - 2 weeks

Question 8

In primary viremia, varicella zoster virus infects the liver and spleen, called the reticuloendothelial system which is composed of phagocytic cells. After 2 weeks it starts infecting immune cells. Which immune cell is most commonly infected?

1 - T cells
2 - B cells
3 - macrophages
4 - leukocytes

Answer 8

1 - T cells

Once T cells are infected, this is secondary viremia

Question 9

Once T cells have been infected, called secondary viremia, T cells begin producing proteins. These proteins then bind with receptors where?

1 - neurons
2 - respiratory cells
3 - renal cells
4 - skin cells

Answer 9

4 - skin cells
- once the T cells reach the skin, the virus is released which then infect keratinocytes and produce the lesions associated with chickenpox

Question 10

Once T cells have been infected, called secondary viremia, T cells begin producing proteins. T cells then release the varicella zoster virus into keratinocytes. What do other uninfected cells produce to stop them from becoming infected?

1 - INF-a and INF-B
2 - IL-6
3 - TNF-a and IL-6
4 - INF-a and TNF-a

Answer 10

1 - INF-a and INF-B
- interferons that inhibit viral replication
- this is why we have lesions and then normal skin in between the lesions

Question 11

Although the majority of the varicella zoster virus are killed off by the host immune system, some of the virus is able to move away from the skin and survive where?

1 - ganglion (collection of neurons)
2 - cardiac tissue (pericarditis)
3 - space around the lungs
4 - genitals

Answer 11

1 - ganglion (collection of neurons)
- those that travel here do not get destroyed by the immune system and remain dormant

Question 12

Varicella zoster virus that remain in the ganglion are able to avoid the immune system and remain dormant. Which 2 of the following does the Varicella zoster virus begin a latent phase?

1 - facial nerve ganglion
2 - trigeminal nerve ganglion
3 - dorsal root ganglion
4 - sacral ganglion

Answer 12

2 - trigeminal nerve ganglion
3 - dorsal root ganglion

If patient becomes immunocompromised the virus can become active again

Question 13

If the varicella zoster virus is dormant in the trigeminal nerve ganglion and dorsal root ganglion it can become active if the patient is immunocompromised. The active infection can travel anterogradally to the skin and infect specific dermatomes supplied by that nerve. What is this called?

1 - meningitis
2 - herpes zoster (shingles)
3 - herpes simplex virus-1
4 - herpes simplex virus-2

Answer 13

2 - herpes zoster (shingles)

Question 14

Secondary bacterial infection is a common complication of varicella zoster virus. Which of the following is not caused by varicella zoster virus?

1 - hepatitis
2 - acute kidney injury
3 - pneumonia
4 - encephalomeningitis

Answer 14

2 - acute kidney injury

Use of NSAIDs to treat fever like symptoms may increase risk of these

Question 15

Patients typically present with symptoms of chickenpox 2 weeks after infection. Which of following is a common symptom patients present with?

1 - fever
2 - headache
3 - overall weakness
4 - all of the above

Answer 15

4 - all of the above
- essentially flu like symptoms

Question 16

Once flu like symptoms have started, typically how long is it before patients present with the typical chickenpox skin lesions?

1 - 24h
2 - 4 days
3 - 7 days
4 - 21 days

Answer 16

2 - 4 days

Question 17

Once lesions present, where do they typically appear?

1 - head and trunk
2 - hands and feet
3 - head and hands
3 - trunk and hands

Answer 17

1 - head and trunk
- can appear anywhere, but most common

• lesions are associated with itchiness
• start as macules then to papules and finally into vesicles
• ulcers in the mouth can also form

Question 18

Once the lesions are established, how long is it before they crust over and fall off?

1 - 4 days
2 - 1 week
3 - 2 weeks
4 - 3 weeks

Answer 18

1 - 4 days

Question 19

As varicella zoster virus is very contagious. Which of the following are correct regarding how contagious varicella zoster virus is?

1 - contagious 4 days before the rash
2 - contagious 5 days after rash appearance
3 - contagious for 2 weeks either side of infection
4 - all of the above

Answer 19

1 - contagious 4 days before the rash
2 - contagious 5 days after rash appearance

Question 20

In patients with shingles, is the infection systemic or is it just specific patches of skin that are affected?

Answer 20

• specific patches of skin
• skin affected relates to the dermatome that has been infected

Question 21

Shingles affects specific patches of the skin related to the infected dermatome. What symptoms do patients present with?

1 - pain
2 - itchiness
3 - tingling
4 - all of the above

Answer 21

4 - all of the above

• pain can last >90 days called postherpatic neuralgia

Question 22

Which 2 parts of the body are typically affected in shingles?

1 - legs
2 - arm
3 - body
4 - torso

Answer 22

3 - body
4 - torso

• rash typically clears after 4 weeks

Question 23

How is chickenpox and shingles diagnosed?

1 - blood test for viral antibodies
2 - PCR for viral DNA
3 - skin biopsy
4 - clinical diagnosis

Answer 23

4 - clinical diagnosis
- all can be done, but NOT commonly

• tzank test can used to confirm diagnosis, where tzank, multi-nucleated cells can be identified on biopsy of affected skin

Question 24

What is the most common treatment for chickenpox?

1 - varicella zoster immunoglobulins
2 - cryotherapy of lesions
3 - topical steroids
4 - topical anti-piuretics

Answer 24

4 - topical anti-piuretics
- essentially helps with rash

• may provide analgesia and NSAIDs, but NOT aspirin to help with flu like symptoms
• varicella zoster immunoglobulins are given in immunocompromised patients

Question 25

Is varicella zoster virus dangerous in pregnant women?

Answer 25

• yes
• can be very dangerous for mum and foetus

Question 26

Patients over what age can be given oral aciclovir which can reduce the course of chickenpox. But what age must they be above?

1 - 6
2 - 9
3 - 12
4 - 16

Answer 26

3 - 12

• oral aciclovir can also be given to adults with shingles from 3 days of blister formation

Question 27

Is their a vaccine available for shingles?

Answer 27

• yes
• typically offered to adults >60