MICRO: Herpes Flashcards
(25 cards)
Human Herpes Virus Types?
Herpes viruses that set up latent infection in Sensory Nerve Ganglia?
HSV1
HSV2
Varicella Zoster (HHV3)
Herpes viruses that set up a latent infection in B Lymphocytes?
EBV (HHV4)
CMV (HHV5)
Kaposi Sarcoma (HHV8)
Herpes viruses that set up a latent infection in T Lymphocytes?
HHV6
HHV7
Herpes viruses that set up a latent infection in Epithelial Cells?
EBV (HHV4)
CMV (HHV5)
Examples/Characteristics of Alphaherpes Viruses?
HSV 1 / 2, VZV (HHV3)
Rapid growth in cell culture
Neuronal latency
Examples/Characteristics of Betaherpes Viruses?
CMV (HHV5), HHV6
Slow growth
Affinity for CD4 lymphocytes
Examples/Characteristics of Gammaherpes Viruses?
EBV
Grow only in lymphoblastoid cell lines
Affinity for B lymphocytes
Structure of Herpes Virus?
Linear double stranded DNA virus
Host Factors Influence on HSV Severity
Congenital deficiencies in humoral immunity do not appear to be significant risk factors for serious primary or recurrent HSV disease
Congenital and some acquired deficiencies in cell-mediated immunity are associated with severe HSV disease- severe and prolonged HSV infections occur in transplant recipients and individuals infected with HIV
Manifestations of Primary HSV1 Infection
Manifestations of Primary HSV2 Infection
Three major patterns of disease in neonatal HSV Infection?
– Lesions of skin, eyes, and mouth
– CNS disease with/without SEM
– Disseminated disease (involving multiple organs) with/without vesicles (most severe)
Untreated mortality exceeds 80% in disseminated disease, and 50% in CNS disease
Treatment of HSV Infection
MOA?
Acyclovir: Converted by viral thymidine kinase to active acyclovir monophosphate; cellular enzyme catalase converts acyclovir monophosphate => acyclovir triphosphate => competitively inhibits viral DNA polymerase
Resistance: uncommon. generally only seen in immunocompromised patients after long duration of acyclovir treatment. Consider Foscarnet or Cidofovir
Herpes Infection affecting the Skin/Face?
Herpes Gladiatorum
________ is the causative agent of varicella (_________) and zoster (____________)
HHV3 is the causative agent of varicella (chicken pox) and zoster (shingles)
Pathogenesis of VSV
Primary VZV Infection (Incubation, Rash Development, Infectious)
Complications of VSV Infection?
Varicella in Pregnancy?
VZV Reactivation
What is Post-herpetic Neuralgia a complication of?
Otological complication of VZV reactivation, due to reactivation of latent virus in the geniculate ganglion with spread of infection to the 8th cranial nerve?
Triad of Presentation?
Treatment?
Ramsay Hunt Syndrome
Triad of:
- ipsilateral facial paralysis
- ear pain
- vesicles in the auditory canal or on the auricle
Early treatment (acyclovir and steroids) should be instigated to avoid complications (permanent facial nerve dysfunction)
Neonates that should receive post-exposure prophylaxis to VZV?
