Term
HSV-1
morphology
transmission
clinical (note: any of these can also be caused by HSV-2)
dx |
|
Definition
DS linear DNA
enveloped
icosahedral
@ neutral pH, infected cells can fuse forming syncytia-seen in smears as multinucleated giant bodies, contain Cowdry A inclusion bodies
direct contact of mucous membranes (oral)
sex
travels up sensory nerve to sensory nerve ganglia, where it replciates, then returns along the sensory nerve fibers to produce skin lesions
Gingivostomatitis (cold sores)
-Reactivation occurs when pt is stressed
Herpetic keratitis of the eye: most common cause of corneal blindness in U.S.
Encephalitis: #1 cause of viral encephalitis in U.S., usually reactivation of latent HSV-1
Tzanck prep: multinucleated giant cells and intranuclear inclusion bodies (Cowdry A)
viral culture
PCR
serology
DFA |
|
|
Term
HSV-2
morphology
transmission
clinical (note: any of these can also be caused by HSV-1)
dx |
|
Definition
DS linear DNA
Enveloped
Icosahedral symmetry
same as HSV-1
Genital herpes
-reactivation is less painful, vesicles last for fewer days
Neonatal herpes: acquired during birth
-a TORCH organism
-disseminated
-CNS
-skin
-eye
Herpetic whitlow
Disseminated herpes infxn of organs
Tzanck prep: MNGC, intranuclear inclusion bodies
same as HSV-1 |
|
|
Term
Varicella-Zoster virus
morphology
transmission
clinical
dx |
|
Definition
DS linear DNA
enveloped
icosahedral symmetry
evades immune response - latent in dorsal sensory ganglia
Varicella is highly contagious!
Zoster: reactivation from dorsal root ganglion
aerosols, disseminates hematogenously
infects membranes, skin, neurons
self-limiting in immune competent pts
Varicella (Chicken pox):
2 wk incubation
fever & headache
rash: first erupt on trunk and face, pts are infectious until lesions scab over
pneumonia or encephalitis in immunocompromised pts
Zoster (shingles):
single dermatome districtuion
-Herpes Zoster ophthalmicus: vesicles on one side of forehead and tip of nose (CN V) may be associated with severe corneal involvement (similar to HSV), can lead to blindness
Secondary bact infxns: S. aureus, S. pyogenes
vesiscles: few drops on the top of a rose petal
Tzanck prep: MNGC w/ intranuclear inclusions |
|
|
Term
Cytomegalovirus
morphology
transmission
clinical
dx |
|
Definition
DS linear DNA
Enveloped
Icosahedral symmetry
Virus present in milk, saliva, urine, tears, semen, cervix
occurs w/ prolonged exposure, such as day care centers
sex
Asymptomatic infxn (latent phase) - leukocytes
TORCH
CMV mononucleosis
Reactivation in immunocompromised pts
-pneumonia, *retinitis* (HIV pts), esophagitis, disseminated disease
opportunistic infxn, controlled by CMI
CMV shell viral culture: blood buffy coat (white cells) cultured overnight, then centrifuged, release Ag
Serology
Histology: enlarged (cytomegalic) cells w/ intranuclear cytoplasmic inclusion bodies ("haloed," "owl's eye" inclusions)
PCR testing for CMV DNA |
|
|
Term
Epstein-Barr virus
morphology
transmission
clinical
dx |
|
Definition
DS linear DNA
Enveloped
Icosahedral symmetry
Intimate contact from shedders
Infects human B-cells and transforms them
-binds to C3d receptor
-EBV DNA enters cells, latent
-some proliferate
-infected cell disappear, as if destroyed
Infectious mononucleosis: fever, sore throat, severe lethargy, enlarged LN & spleen
Assoc with Burkitt's B-cell lymphoma
OHL in AIDS patients
Nasal pharyngeal carcinoma
*Elevated heterophil Ab*
WBC will show elevated "atypical lymphocytes" - Downey cells
Serology: IgM against viral capsid antigens - VCA, EBV-EA, EBNA
*Monospot: agglutination of RBC* |
|
|
