Herpesviridae Flashcards
Genome of herpes?
Double stranded
Linear
Describe virion of herpes?
Icosahedral
Three subfamilies of herpes?
Alpha
Beta
Gamma
Rapid growth?
Alpha
Slow growth?
Beta (bagal)
Latency in sensory ganglia
Alpha
All herpesvirus have identical MORPHOLOGY and cannot be distinguished under what?
EM
Latent infection for alpha?
Neurons
2 genus of alpha
Simplex
Varicello
Official names of all alpha
HHV 1-3
HHV 1 - HSV1
HHV 2 - HSV 2
HHV 3 - VZV
Genus for beta
Cytomegalo
Roseola
Genus for gamma
Lymphocrypto
Rhadino
Common names for beta
CMV (HHV5)
HHV6
HHV7
Hsv 1 and 2 genome share?
50-70% homology
Cross reactive epitopes with each other and VZV
Only natural host for HSV
Man
Most common form of infection results from a KISS given to a child
HSV
Generally HSV 1 causes infection where?
Above the belt
40% of genital sores are?
HSV1
Primary infection or reactivation HSV?
- short lived viremia
- spread to the craniospinal ganglia
- irradiation or psychological stress
Primary
Primary
Reactivation
Most common manifestation of 1• herpetic infection
Acut gingivostomatitis
What is the manifestation of acute gingivistomatis?
Pain and bleeding of gums
Recurrence of oral hSv
Herpes labialis
Lesions found in herpes labialis
Papules then vesicles
Vesiculoulcerative lesion; prone to 2• bacterial infection
Genital herpes
Common conplaint with genital herpes
Dysuria
One of the most serious complications of herpes simplex
Ensephalitis
2 forms of herpes simplex encephalitis
Neonatal
Focal disease
Global involvement; brain is liquified
Neonatal
In focal disease what part of brain is usually involed
Temporal
Given in all cases of HSE
Acyclovir
Baby usually infected perinatally during passage thru birth canal
Neonatal herpes simplex
In neonatal herpes simplex, most common organs involved
LAB
LIVER
Adrenals
Brain
Only means of prevention for neonatal hsv
Cesarian to mothers
3 categories of disease of neonatal herpes simplex
Lesions in skin; disseminated ds to organs; enceph
Occurs in immunocompromised and resembles chicken pox
Disseminated herpes simplex
Other cutaneous manifestations pf herpes simplex?
Zosteriform
Eczema herpeticum
Herpetic whitlow
Rare presentation of herpes simplex wherein dermatomal distribution
Zosteriform
Lesions that typically affect the fingers( dentists and hospital staff)
Herpetic whitlow
Rapid result but cannot distinguish bet hSV and Vzv
EM of vesicle fluid
Can distinguish bet HSV and VZV
ImmunoF of skin scrapings
Definitive diagnostic approach for HSV
Virus isolation!!
Mgt for hsv that is oral only and more expensive than acyclovir
Famcyclovir
Vala”
Main target organ of varicella
Skin
Vzv becomes latent in the?
Cerebral or dorsal root ganglia
Vzv entry via?
Respiratory tract
True or false?
Diagnosis of varicella is made on clinical grounds alone
True
Most common conplication of varicella
Bacterial innfection
Earliest symptoms of varicella
Malaise and fever
Order of rash site?
Trunk, face, limbs, mouth
Also known as shingles
Herpes zoster
Intensive pain in zoster that may last for months
Postherpetic neuralgia
Zoster transmitted to the fetus in the first 20weeks (very rare!!)
Congenital vzv infection
Vzv can cross the placenta on later stages to infect fetus leading to
Neonatal varicella
Zoster Ig should be given to?
Pregnant who had contact with vzv cases;
Infants whose mothers had it 7days before delivery or upto14 days after delivery
Vesicular fluid bet the 2 can be differentiated in EM
HSV and Pox
Antiviral thrapy only given to these vzv patients
Gt 50 years!!
Beta herpes virus that is Very species and cell type specific
Cmv
Only known host for cmv
Humans
Once infected virus remains in the person for life and nay be reactivated from TIME to TIME
Cmv
Perinatal infections of cmv occurs at
Genital secretions or breast milk
Postnatal infections of cmv occurs at?
Saliva
Syndrome of infective mononucleosis
Fever
Lymphadenopathy
Splenomegaly
Second most common cause of ment handicap, next to trisomy 21
Congental CMV infection
Candidate vaccine for CMV
Towne strain
Major target cell of ebv
B lymphpcyte
Ebv receptor in cells
Cr2 or cd21
Three classes of ebv antigens
Latent phase;
Early; late
Ebv: Nonstructural proteins whose synthesis is nlot dependent on viral DNA replication
Early
Ebv: includes ebna and lmp
Latent phase antigens
Ebv is transmitted via
Saliva( kissing)
2 disease association of ebv in aids patients
Oral leukoplakia
Chronic interstitial pneumonitis
These atypical cells are present in the blood in IM
Downey cells
Diagnosis of IM?
Heterophil antibody test pr
Detn of igM
Malaria infection is a cofactor
Burkitts lymphoma
Gene that is associated w burkitts lymphoma
C myc
Malignant tumor of the squamous nasopharynx; most common tumor in men;
Nasopharyngeal Ca
Occurs exclusively in males who had inherited a defective gebe in the X chrom; accts for half the fatal cases of IM
Ducan x linked
Screen for early lesions of npc and monitoring treatment
AntiEBV VCA IgA
Vaccine developed for ebv
MA antigeb gp 340/220
Main target cell for hhv7
T cells
Genome resembles cmv
Hhv6
Cell receptor for HHV6
CD46
HHV6 and 7 transmitted thru
Saliva and breast feedingg
As early as what age does hhv 6 and 7 occur?
4 mos old
Reactivation common in transplant px and during pregnancy
HHV6
Disease associated with HHV 6and 7
Roseola infantum ( 6th ds or exanthem subitum)
Cause of roseola from hhv 6
6B variant
Its genome is 75% G + c, highest among all herpesvirus
B virus
Disease in humans by B virus
Acute ascending myelitis
Encephalomyelitis