Herpes Virus Flashcards
Where is viral envelop derived from?
Host cell nuclear membrane
Which is tegument?
A structural protein btw envelop and capsid
Types of herpes virus?
HSV 1$2 Varicella zoster virus Epstein Barr virus Cytomegalovirus Human herpes virus 678
Class of herpes virus?
Alpha (HSV $ VZV)- sensory ganglia inf
Beta (CMV)- salivary gland $ organ inf
Gamma ( EBV)- B $ T cell inf
Types of Herpes simplex virus
Type 1$2
HSV 1?
Mouth inf Spread by direct contact Infection above waist Virus remains latent in ganglia Trigeminal nerve- nerve of the face
HSV 2?
Genitalia inf
Spread by venereal- sex
Inf below waist
Sacral nerves
Envelop of HSV contains?
Glycoproteins B D H
B$D- absorption and penetration into host cell
H- release of the virus
Pathogenesis of HSV?
Virus enter through defects skin/ mucous Multiply locally Enters the cutenous nerve fibers Replication in ganglia Migration to skin/ mucosa.
Causes cutenous and mucosa lesion.
Clinical manifestation of HSV?
Depends on site of inf, age, immune status of host, antigenic type of virus
Lesion on buttocks of infant?
( napkin rash)
Cutenous inf of HSV looks like?
Thin walled vesicle
A ballooning
Degeneration of intra epithelial cells
The underlying basal layer is usually intact with the vesicle
The base of vesicle contains multi nuclear cells (Tzanck cells) with eosinophillic inclusion bodies
The base of the vesicle in HSV contains?
Tzanck cells with eosinophilic inclusion bodies
What happens when the vesicle of HSV cutenous lesion breaks down?
Ulcer forms in the mucous $ non-keratinizing epithelia
The lesion in fever blister/ herpes fibrils is caused by?
Virus deactivation in febrile ( showing sign of fever) patient
Occupational cutenous herpes?
Hermetic whitlow seen in doctors, dentist and nurses
Eczema herpeticum (kaposi varicelliform) of cutenous inf of HSV?
Eruption caused by herpes inf in children with eczema
Arises from pre-existing skin disease usually atopic dermatitis
Mucosal inf of cutenous inf in HSV?
Buccal mucosa is the most common site
Gangivostomatittis
Pharyngitis - most frequent in primary $ recurrent inf
Opthalamic inf of cutenous inf in HSV?
Acute keratoconjuctivitis ( itself or by extension from facial herpes)
Most common cause of corneal blindness
Follicular conjunctivitis in Cutenous inf of HSV
Vesicle on eyelids
Cornea may be involved with typical branching dendritic ulcers
Nervous system inf of HSV?
HSV encephalitis- acute onset with fever
Focal neurological symptoms
HSV meningitis- self limiting disease usually leave in a week
Rarely transverse myelitis or Gillian barre syndrome
What causes sacral autonomic dysfunction
Nervous system inf of HSV
What can cause bell’s palsy
HSV ( nervous inf)
Visceral inf ofHSV?
HSV esophagitis causes dysphagia, substernal pain, weight loss
Respiratory tract inf causing tracheobronchitis, pneumonitis
Erythema multiforme
Genitalia inf of HSV?
Lesion on penis, urethra, cervix, vulva, perineum
Primary inf is usually more serious
Fever and malaise
Vesicular-ulcerated lesion may be painful
Congenital inf of HSV
Transplacental inf - congenital malformation
If mother has HSV1- fetus multi organ involvement with or without encephalitis
Mortality rate is high
If mother has HSV 2- post neonatal inf common in eye , mouth and skin
Caserian section may prevent inf to the neonate
Diagnosis of HSV?
Tzanck cell smear with Toluidine blue o or giemsa stain
FAT
PCR
Isolation from amnion cell, embryonic kidney cell, chick embryo
ELISA
NEUTRALIZATION TEST
COMPLEMENT FIXATION TEST
CHEMOTHERAPHY - idoxyuridine ( topical use for skin and eye inf)
Acyclovir$ vidarabine- management of deep and systemic inf
Acyclovir - to avoid encephalitis
Valaciclovir $ famiciclovir are more effective as oral agents
