5- Herpes

Question 1

taxonomy of Herpes

Answer 1

Herpesviridae
- Alphaherpesvirinae
- Herpes simplex virus 1 (HSV-1)
- Herpes simplex virus 2 (HSV-2)
- Varicella-zoster virus (VZV)

• Betaherpesvirinae
  
  • Human cytomegalovirus (HCMV)
• Gammaherpesvirinae
  
  • Epstein-Barr virus (EBV)

Question 2

morphology of Herpes

Answer 2

• spherical
• Complex
• double stranded DNA
• Surface antigens:
  
  • glycoprotein spikes

Question 3

cultivation of Herpes

Answer 3

tissue cultures / hela

Question 4

antigenic properties + virulence of Herpes

Answer 4

-glycoprotein spikes on supercapsid
-viral capsid proteins (VP1, VP5)

Question 5

pathogenesis of Herpes

Answer 5

• source = infected person / carrier
• trans. method=
  *HSV1 = DIRECT ORAL CONTACT
  *HSV2 = sexual contact
  *VARICELLA =
  contact
  air borne

*(beta) cytomegalovirus =
- CONTACT
- SEXUAL +
- BLOOD transfusion
- TRANSPLACENTAL

*(gamma) Epstein-Barr = contact

• gate =

Question 6

pathogenesis + CLINICAL MANIFESTATION of Herpes

Answer 6

*HSV1 = oral herpes / cold sores
# primary infection in lips -> moves to ganglia, remains latent there-> virus reactivates and moves to original site.
# fever, sore throat, vesicular ulcers on oral mucosa / skin around mouth

*HSV2 = genital herpes
# infection in vagina and cervix (in women) * in penis and (in men)
#fever, malaise, urinary retention

*VARICELLA-ZOSTER = chickenpox & shingles
# “Chickenpox” an initial infection ->forms vesicles that rupture and become scabs -> virus moves to ganglia remains latent
# in adulthood virus reactivates and causes “Shingles” ->skin vesicles reappear
# fever, skin rash

*(beta) cytomegalovirus =
# spreads to all organs ->causing giant cells with nuclear and cytoplasmic inclusions -> becomes latent
# sore throat, swollen glands, swollen tonsils,

*(gamma) Epstein-Barr =
# virus replicates in oral epithelia and Tonsillar B-cells -> it promotes growth of B-cells ->t cells kill and limit B-cells growth but -> virus remains latent in memory B-cells. -> virus becomes active whenever B-cells activate.
#high fever, sore throat, grey-white exudate, skin rash

Question 7

diagnosis of Herpes

Answer 7

• PCR
• ELISA
• tzanck smear (from skin lesions)

Question 8

treatment of Herpes

Answer 8

• Antiviral medications (but doesn’t cure the virus.)

Question 9

prophylaxis of Herpes

Answer 9

no vaccine .

only - Varicella-zoster virus (VZV)
has vaccine - “(live) varicella vaccine”

Question 10

Enzymes for Herpes

Answer 10

• DNApolymerase for viral-DNA replication