Herpesvirus Flashcards
Alpha Herpesviruses
Herpesvirus 1, 2, 3
1&2 = HSV
3= VZV
Gamma Herpesviruses
4 = EBV
**also #8?
Beta Herpesvirinae
Herpesvirus 5, 6, 7
5 = CMV
6 = HHV6
7 = HHV7
Herpesvirus genome and structure
dsDNA genome
- Envelope, tegument, and capsid
- Glycoprotein spikes
Herpesvirus produces proteins in what three phases
- Immediate Early proteins (alpha) regulate gene transcription
- Early proteins (Beta) DNA pol and TF’s
- Late Proteins (Gamma) = structural proteins
Herpesvirus envelope is from ______
the nucleus
Herpesvirus encodes what two enzymes
DNA-dependent DNApol
Thymidine Kinase
80% of Herpesvirus are ______
asymptomatic
Oral herpes (acute gingivostomatitis) incubation time
One week
Cold sores =
herpes labialis
Herpes labialis prevalence?
20-40%
Herpes Keratitis most frequent cause of ______
blindness
Major signs of herpes keratitis
- Unilateral red eye
- Vesicular skin rash
- Folicular conjunctivitis
- DENDRITIC CORNEAL ULCER (= hallmark sign)
Herpes keratitis Tx
Acyclovir cream 3%
Herpes Whitlow caused by
HSV 1 or 2
Herpes whitlow incubation period
2-20 days
Herpes whitlow infection characteristics (3)
Fever
Malaise
Treatmtent is SELF LIMITING
Herpes gladiatorum appearance and treatment
Head and neck blister cluster
Treatment is acyclovir
Eczema herpeticum epid, features, incubation, and Tx
- Rare, usually children
- Severe disseminated disease at pre-existing sites of skin damage
- Incubation of 5-12 days
- Tx = Acyclovir and ANTIBIOTICS to prevent 2’ infection
Genital Herpes systemic effects
Fever, flu-like symptoms, swollen lymph nodes
Genital HSV2 lasts about _______
one month
HSV encephalitis usually caused by
HSV1
HSV accounts for __% of all encephalitic viral infections
10-20%
HSV encephalitis phases
Prodrome = fever and nausea
Encephalopathy = either acute or subacute
HSV encephalitis has a predilection for edema and hemorrhage in ______
temporal lobe
CSF appearance in HSV encephalitis
Glucose and protein = mostly normal
Elevated WBC (mostly lymphocytes)
RBC found becaue of hemorrhage
HSV meningitis mostly caused by ____
HSV2
50% of HSV meningitis cases are _____ and 50% are _____
Primary and Secondary
HSV enceph vs. meningitis – CSF appearance
Enceph has way higher RBC
Meningitis has higher WBC and Protein
Neonatal herpes caused mostly by
HSV2
Neonatal HSV can be transmitted…
- vertically from mom
- from another neonate
Symptoms of neonatal HSV (after vs before birth infections)
After Birth = Many confined to skin, eye, and mouth. Encephalitis in 35%. Disseminated in 25%.
Before birth = Premature birth, low birthweight, microcephaly, hydrocephalus, chorioretinitis, vesicular skin lesions
- HSV replicates in ______ cells.
- Hangs out in the ______ and______ ganglia.
- Establishes ________
- epithelial
- trigeminal and sacral
- latency
HSV1 and 2 cause 3 types of infections:
- Lytic (replication in mucoepithelial cells, disease @ lesion site)
- Latent (neuronal)
- Persistent (in lymphocytes and MQ
Cell death during HSV infection can result from _____, _____, or _______
- Virus induced inhibition of cell molecules
- DNA degradation
- Cytoskeleton disruption
Other cellular hallmarks of HSV infection
- COWDRY bodies (acidophilic intranuclear inclusion)
- Syncitia
Innate ___________ may be sufficient to limit HSV infection
innate protection by interferon
Antivirals for HSV
- Anything ending in “cyclovir” (A, Pen, Val, Fam)
- Adenosine Arabinoside
- Iodo-deoxyuridine
- Trifluridine
Varicella is a result of _______ infection of VZV
primary
Varicella Pox appearance
vesicle, pustule, crust, scabbed lesions
Lesions appear for 3-5 days
Varicella incubation period
about 2 weeks
When is chickenpox contagious?
2-3 days before rash appears
__________ can be observed during the course of chickenpox infection
ALL stages of lesions
Varicella rash characteristics and associated diseases?
- more prevalent on trunk
- SCALP presence distinguishes it from other rashes
- May cause Interstitial PNA in 20-30% of adults (from inflammatory rxn at site of lesion)
Herpes Zoster is a _______ infection of __________ Varicella
recurrent infection of latent VZV
Shingle rash is usually ________ and forms a __________
unilateral
forms a “dermatomal pattern”
VZV transmission via ________, rarely _____
Inhalation
Rarely transplacental
VZV initially infects the _________ and spreads to ________ by VIREMIA
respiratory tract
RE system