Varicellar Zooster Virus

Question 1

What is a highly contagious endemic disease, known to be a classic disease of childhood?

*>90% adults show serological evidence of infection

Answer 1

VZV

*Human Herpes 3 Virus

Question 2

How is VZV transmitted from one person to the next?

Answer 2

• Through respiratory droplet

*The virus replicates in the nasopharynx

Question 3

What’s the primary disease caused by the infection with VZV?

*Complications from primary infection: (vesicular rash, fever, lymphadenopathy)

Answer 3

Varicella/Chicken pox

*VZV infects u and remains latent or dormant in the dorsal root ganglia. Certain factors such as immunosuppression reactivates it. It then travels along the nerve fibers to the skin and mucous membranes, causing a painful rash and blisters (herpes zoster/shingles)

Question 4

What complications are seen with the secondary infection of VZV which is shingles/herpes zooster?

Answer 4

• ‘Herpes Zoster Opthalmicus’: trigeminal nerveresponsibke for sensation of the eye and face is affected

Question 5

What’s a viral infection of the nerve that supplies sensation (touch and pain) to the eye surface, eyelids, skin of the forehead and nose (trigeminal nerve).

Answer 5

The nerve infected is called the trigeminal nerve (it’s the infection of the opthalmic region of this nerve tht causes the herpes zooster opthalmicus.)

Question 6

How to diagnose VZV in the patient?

Answer 6

• Direct detection:
  -PCR (routine for herpetic encephalitis)
  -Immunofluorescence (can distinguish HSV and VZV)
  -Electron Microscopy (rapid but can’t distinguish HSV and VZV)
• Virus isolation (2-3 weeks)
• Serology
  -IgG-> past infection
  -IgM-> recent primary infection

Question 7

What is the treatment used against VZV?

Answer 7

• Acyclovir often prescribed to accelerate resolution
• Herpes Zoster –acyclovir, Valacyclovir and famciclovir (similar efficacy)

Question 8

How to prevent infection with VZV?

Answer 8

• Isolation of infected patient,
• general hygienic practices around infected individuals
• Live attenuated vaccine (for both varicella and herpes zooster)
• Zoster Immunoglobulin (ZIG)-very expensive- passive immunization–Inthe case of pregnant women