Herpesviruses Flashcards
Herpes is an
Enveloped DNA virus
Human Herpes Virus
HSV-1
HSV-2
VZV
EBV
CMV
HHV-6
HHV-7
Kaposi sarcoma-associated herpes virus
Human Herpesviruses
Ubituitis
DsDNA virus (low mutation rate)
Lipid envelope (laible, unstable in the environment)
Replication
envolpe glycoproteins interact with cell surface resectors
Fuses with envelope of cell membrane releasing nucleocapsid into cytoplasm
Enzymes and TF carrient into cells
genome transcriped and replicated
Early proteins (DNA dependend DNA polymerase)
Lytic phase
Active causes primary infection and reactivation
Latent phase
Limited gene expression
Latency
Alpha
Latent in sensory neurons
Painful skin/mucous membrane disease
HSV-1
HSV-2
VZV
Beta
Latent in white blood cells
CMV
HHV-6
HHV-7
Gamma
Latent in lymphocytes
EBV
Kaposi sarcoma-associated herpes virus
HSV-1 and HSV-2
primary infection- enters through mucosal surface or epithelium
Transport to sensory ganglion where it lays latent
HSV 1 and 2 Transmission and Cilinical presentation
Direct skin contact
Painful skin/mucous membrane disease (pain begins before lesion)
Progress from vesicles to ulcers
Also ocular neuro and disseminated disease
HSV 1 and 2
Oral herpes: usually asymptomatic, otherwise severe
systemic symptoms
Gingivosomatitis
Pharyngitis
Reccurent: HSV-1 more common due to latency in trigeminal ganglia (hepes labias)
Genital herpes: usually asymptomatic, otherwise severe
HSV 2 more likely due to latenct in sacral ganglia
HSV cutaneous manifestations
Herpatic whitlow (fingers)
Eczema herpeticum ( infection in excema)
Erythema multiforme (immune-mediated that presents with target lesions)
HSV ocular and neurologic
Keratitis
Retinitis
Encephalitis (HSV-1)
Meningitis/meningoencephalitis
Bell’s Palsy
HSV other clinical manifestations
Disseminated disease
Virema
HSV diagnosis
Not easily cultured
Testing depends on site of disease (PCR most sensitive)
PCR from sterile site
Visualization of organisms in tissue biopsy (if organ involvement)
ZVZ
intitial replication in respiratory epithelial cells
forms syncytia
cell mediated immunity essential to control infection
Transmission of VZV
Aerolization from skin lesions (indicates airborne lesions)
Clinical presentation: chicken pox
different stages of development
vesicles refered to as dew drops on a rose petal
VZV reactivation
shingles/zoster
painful unilateral vesicular eruption in dermatomal distribution
ZVZ complications
Post hepratic neuralgia (most common)
Herpes zoster opthalmicus
Ramsay Hunt syndrome
VZV detection and prevention
PCR detection
vaccine for varicella (live-attenuated, Oka strain of ZVZ)
recombinant zoster vaccine
CMV
transmission person to person
immunocompetent hosts
immunocompetent people: mononucleosis
Congenital disease (primary CMV in pregnant mother)
causes microcephaly, growth restriciton, hepatosplenomegaly
nonhereditary sensorineural hearing loss
Immunocompromised: reactivation from nonspecific disease to sever end-organ disease
CMV diagnosis
serum IgM or IgG
tissue biopsy: owls eye inclusion bodies
HHV-6 and HHV-7
transmitted through salivia
poseola infantum/6th disease
high fever, fever breaks, RASH
