herpes virus Flashcards
Diagnose Herpes simplex virus-1 and HSV-2 from clinical presentation and lab findings. Differentiate the pathogenesis of HSV in adult and neonatal patients. Compare and contrast the pathogenesis of chickenpox and shingles. Recommend immunization for varicella-zoster virus. Describe how acyclovir inhibits herpesviruses.
describe the Herpes virus
2x stranded DNA
Capsid
Glycoprotein envelope
the glycoprotein envelope makes the herpes virus….
sensitive to heat (labile)
mediates attachment of the HSV to host cells
glycoproteins whoch act as receotirs
targets for herpes therapy
DNA polymerase and thymidine kinase
generally causes lesions “above the waist”
HSV-1
generally causes lesions “below the waist”
HSV-2
location of HSV latency
sensory neurons of neural ganglia
can activate latent HSV infection
UV exposure, menstration, fever, infection, stress and some drug interactions
immune defense to intial HSV infection
interferon and NK
immune defense to spread of HSV infection after intial phase
T cells, activated macrophages
HSV usually aquired by age 2
HSV-1
HSV often aquired after sexual maturity
HSV-2
natural host of HSV
humans only
epidemiologically associated with cervical cancer
HSV-2
causes genital herpes
1 and 2
causes gingivostomastitis
1
causes keeratocinjunctivitis
1
causes cutaneous herpes
1 and 2
causes encephalitis
1
causes neonatal herpes
2
causes meningioencphalitis
2
causes herpes labilalis (cold sores)
1
causes childhood pharyngitis
1
Herpes whitlow def
sores on the hands of dentists
signs of congentital herpes at birth
hepatospenomegaly, microencephaly, vesicles, eye lesions,
will indicate poor prognosis in neonatal herpes
neurological signs
microscopic findings of herpes lesions
multinucleated giant cells in tzank smears and intranuclear inclusion bodies
4 ways to lab diagnose HSV
Microscopy
Cell culture (immunoflorence or DNA assay)
PCR
Serology
standard anti-herpes viral drug
acyclovir
target of acyclovir
thymadine kinase
MOA of acyclovir
nucleoside analog, causes errors in DNA replication or RNA transcription or indirect inhibition od DNA polymerase
used against acyclovir resistant HSV
foscarnet
why anti-virals cannot eradicate latent infection
no DNA replication during that time
main route of VZV transmission
respiratory
reactivation of the latent VZV infection leads to
herpes zoster
latent VZV resides in the…
sensory root ganglion
sx of varicella
malise, skin rash, anorexia, listlessness
adults with varicella may develop
VZV pneumotitis
congenital varicella may lead to
skin scarringm hypoplastic limbs, eye abnormalities and CNS involvement
most significant clincal problem with herpes zoster
post-herpetic neuralgia
syndrome from kids taking aspirin during chicken pox
Reye’s
recommended age for herpes zoster vaccination
60 and older
drug treatment for adult varicella and zoster
acyclovir
