L2 - Herpesviruses Flashcards
What are the 3 subfamilies of Herpes?
Gammaherpesviridae
Betaherpesviridae
Alphaherpesviridae
What are the Alpha HSVs?
HSV1
HSV2
VZV
What are the Beta HSVs?
HHV7
HHV6
CMV
What are the Gamma HSVs?
EBV
KSHV
What does HSV1 cause?
cold sores herpes encephalitis (brain herpes, very rare)
How can children become blind from HSV1?
touch cold sores
rub eyes
What does HSV2 cause?
genital herpes
What does VSV cause?
Chicken pox
shingles
Why is shingles an issue with the ageing population?
nerve damage on skin
long term pain
what 4 diseases does KSHV cause?
Kaposi’s sarcoma
Multicentric Castleman’s disease
Primary effusion lymphoma
KSHV inflammatory cytokine syndrome
What are the 2 distinct life cycles of HSV?
Lytic
Latent
What occurs during HSV lytic replication cycle?
transcription - IE, DE, late expression
genome replication
assembly
envelopment
Where does HSV remain latent
sensory ganglion
What does shedding in genital areas achieve?
transmission to other sexual partners or mother to infant at delivery
What are the 3 antivirals used for HSV1/2?
acyclovir
valacyclovir
famcyclovir
What do the other 2 HSV1/2 antiviral drugs have over acyclovir?
higher oral availability
How does acyclovir act?
Prevents chain elongation = cell death
Viral Thymidine kinase
cellular kinase x2
Viral + host
polymerase
What is acyclovir an analogue of
guanosine - lacks a ribose moiety
What is the difference between the nucleoside analogues?
Valacylclovir - esterified version of acyclovir
How is genital herpes treated
continuous drug regimen
What drugs are useful for acyclovir resistant strains?
Helicase-primase inhibitors
enhance binding of the complex to DNA - prevents progression through helices/primase catalytic cycles
sticks to DNA - stops movement & replication
What is the name of helicase-primase inhibitors?
BILS 179 BS
How can HSV2 occur in neonates?
skin
eyes
encephalitis
severe neurological disease
How can neonatal herpes be prevented?
caesarean
suppressive therapy to reduce virus shedding from 36 weeks
