DNA Virus - Herpesviridae Flashcards
Classification of Herpesviridae
HHV 1-8
HHV 1 and 2 - Cause HSV 1 and 2
HHV 3 - HZV/Varicella zoster
HHV 4 - EBV
HHV 5 - CMV
HHV6
HHV7
HHV8
General properties of Herpesviridae family
150-200nm size (Second largest)
Icosahedral Symmetry
dsDNA
Subfamilies of Herpesviridae family
Alpha
Beta
Gamma
Alpha subfamily of Herpesviridae family includes which species and site of latency
Species - HHV 1, 2 and 3
Site of latency - Neurons
Beta subfamily of Herpesviridae family includes which species and site of latency
Species - HHV5, 6, 7
Site of latency - Glands and T cells
Gamma subfamily of Herpesviridae family includes which species and site of latency
Species - HHV4 (EBV), HHV8
Site of latency - B cells
Transmission ways of HSV 1 And HSV 2
HSV 1 - Mucosa/Abraded skin
HSV 2 - Sexual/vertical
Latency sites of HSV 1 And 2
HSV 1 - Trigeminal ganglia
HSV 2 - Sacral ganglia
Age group more commonly affected in case of HSV 1 and 2
HSV 1 - Children
HSV 2 - Adults
Clinical features seen in case of HSV 1
Orofacial mucosal lesions
Skin lesions above waist
Encephalitis
Meningitis
Ocular lesions
Clinical features seen in HSV 2
Genital lesions - B/L painful vesicles with painful Inguinal Lymphadenopathy
Below waist
Neonatal herpes( mother to child)
Which HSV grows well on Chick embryo fibroblast
HSV 2 - Grows well
HSV 1 - doesn’t grows well
Which HSV shows more Neurovirulence and drug resistance
HSV 2
Most common site of Orofacial mucosal lesions
HSV 1 M/C
Buccal mucosa
Most common primary lesion in HSV 1
Gingivostomatitis
Most common recurrent lesion in HSV 1
Herpes labialis
CNS Infections are more Common in which HSV
HSV 1»_space; HSV 2
HSV 1 is most common cause of which type of encephalitis
Acute sporadic viral Encephalitis (temporal lobe is affected)
Mollaret meningitis/Recurrent lymphocytic Meningitis is most commonly seen in which HSV
HSV 2
Ocular lesions are most commonly seen in which HSV
HSV 1 > HSV 2
Dendritic corneal ulcers
Genital lesions are most commonly seen in which HSV
HSV 2»_space; HSV 1
Bilateral painful vesicles with Painful Inguinal Lymphadenopathy
Other clinical features seen in HSV
Herpetic whitlow (seen in healthcare workers)
Herpes gladiatorum (Wrestlers herpes)
Eczema herpeticum
Erythema multiforme
Tzanck smear is done for diagnosis of
Done for HSV 1 and 2
Low sensitivity
Can’t differentiate between HSV 1,2 And HZV
Sample taken in case of HSV and are stained by
Lesion - unroof vesicle, Scrap base
Stain with Giemsa nd Wright stain (Romanowsky stain), Toluidine stain
Cytopathic effect seen in case of HSV Infection
3M phenomenon
Multinucleated, Moulding and Margination of Chromatin
+
Cowdry Type A - Lipchultz bodies
Which is most definitive diagnosis exam in case of HSV
Virus isolation - Cell lines
DNA studies and Serology methods of HSV Infection
PCR - Sensitive, can’t differentiate
ELISA - 4 fold increase in antibodies suggestive of HSV
Drug of choice in HSV Infection
Acyclovir - inhibits DNA Polymerase
If Resistance - Foscarnet
HHV 3/Herpes Zoster/Varicella Zoster virus causes which diseases in Children and Adults
Child - Chickenpox
Adults - Herpes Zoster/Shingles
Incubation period of Chickenpox
2-3 weeks
Characteristic rash features in Chickenpox
Versicle surrounded by an erythematous halo (Dew drop on a rose petal)
If in adults - More severe hemorrhagic and bullous lesions
Rash distribution in case of Chickenpox
Bilateral, diffuse, Centripetal distribution (starts on trunk) - then centrifugal spread (flexor surface)
Comes on crops (fever with each crops)
Period of infectivity in case of Chickenpox
2 days before and 5 days after rash
Reservoir, source and Carrier in case of Chickenpox
Reservoir - Humans
Source - patient’s
Carrier - None
Most common Complication of Chickenpox
Secondary bacterial infection
Most common extracutaneous Complication of Chickenpox
CNS Involvement - Benign cerebellar ataxia
Most serious Complication of Chickenpox
Varicella Pneumonia (especially in pregnancy)
Fetal/Congenital Varicella Syndrome timeline and clinical features
Infection within 20 wks of intrauterine life
Cicatricial skin lesions
Limb hypoplasia
Microcephaly
Cortical atrophy
Neonatal Varicella Syndrome causes and max chance of transmission
Mother has varicella in late pregnancy
Max chance of Transmission - 5 days before to 2 days after delivery
Disseminated disease
Treatment of Neonatal Varicella Syndrome
Acyclovir (Prophylactically)
If skin lesion appears - Varicella zoster Immunoglobulin (<94 hrs of exposure)
Vaccine for Neonatal Varicella Syndrome
OKA Strain (2 doses)
Herpes zoster/ Shingles occurs due to
Reactivation - in elderly or immunocompromised patients
Rash distribution in Herpes Zoster/Shingles
Along dermatomes (M/C - D3 to L2)
Unilateral, segmental and Painful
Zoster sine herpete means
Dermatomal pain without skin lesions
Complications of Herpes Zoster/Shingles
Post herpetic Neuralgia (M/C);- Pain at local site
Zoster opthalmicus - trigeminal ganglion, dendritic ulcer
Ramsay hunt Syndrome
Ramsay hunt Syndrome
Involvement of Geniculate ganglion of CN VII
Facial N palsy
Vesicles in EAM, otalgia
Loss of taste sensation on ant. 2/3rd of tongue
Vaccines used in case of Varicella zoster/Shingles
To enhance the immunity
Live attenuated vaccine - Zostavax
Recombinant vaccine - Shingrix
Transmission of Epstein Barr virus (HHV4)
Close contact
Kissing
Sexual intercourse
Blood Transfusion
BM Transplantation
EBV entry via which receptors and acts on which cells
Receptors - CD21/CR2
Leads to activation of Polyclonal B cell
Regulation Proteins for Esptein barr
LMP 1(Latent membrane protein 1) - acts on CD4 Pathway
EBNA 2 ( Epstein barr nuclear antigen 2) - Activates SRC Protooncogenes
VIL10 (Viral interleukin 10) - Antiinflammatory
Epstein barr virus Causes
1) Infectious mononucleosis/Kissing disease - Aka Glandular fever
2) Malignancy
3) Other condition - Duncan Syndrome (Lymphoproliferative Syndrome)
- Hairy cell leukoplakia/oral cell leukoplakia
- Hemophagocytic Lymphohistiocytosis (HLH)
Clinical features and incubation period of Infectious mononucleosis
IP - 4-8 weeks
SHE Feels Shy LAL
Splenomegaly
Hepatitis
Encephalitis
Fever
Sore throat
Lymph node enlargement
Arthralgia
Lethargy
Malignancies caused by Epstein Barr virus
Carcinoma
Lymphoma
Sarcoma
Carcinoma associated with EBV infection
Most common - Gastric Carcinoma
Nasopharyngeal Carcinoma
Lymphoma associated with EBV
Hodgkin’s - mixed cellularity
NHL - Burkitts Lymphoma, DLBL, Post transplant Lymphoma, T/NK cell Lymphoma
Sarcoma associated with EBV infection
Leiomyosarcoma
CBC Microscopic finding in case of EBV
Atypical Lymphocytes (Downy cells) - AKA - Ballurina skirt appearance
Heterophile Antibody detection test done in case of EBV
Paul Bunell test - A/b react with sheep RBCs
Monospot test (Now) - A/b react with horse RBC
Specific antibody test done in case of EBV
Antibody to viral capsid antigen
Antibody to early antigen - Early diagnosis
Antibody to EBNA
Most sensitive and specific test for EBV
Nucleic acid hybridization test
Treatment of EBV
Acyclovir - oral hairy cell leukoplakia
Rituximab
Which is the largest of Herpesviridae
Cytomegalovirus (HHV5)
Transmission of Cytomegalovirus
M/C - Oral, respiratory, body secretions
Less common - Transplacental, sexual
Cytomegalovirus multiplies in which organs
SRK - Mannat(Sleep)
Salivary gland (M/C)
Respiratory tract
Kidney
CMV remains latent in which Organ
Monocytes
Clinical signs of CMV are classified into
Congenital
Perinatal
Immunocompetent
Immunocompromised
Most common infection associated with Congenital defects
Congenital CMV Infection
Clinical features of Congenital CMV Infection
More common - Hepatosplenomegaly, Jaundice, Petechia/Purpuric rashee
Less common - Microcephaly, Chorioretinitis, Cerebral calcification, deafness
Perinatal CMV clinical features
Usually asymptomatic - later on can see complications
CMV clinical features in Immunocompetent pt.
Infectious mononucleosis like Syndrome - Fever, sore throat, No Lymphadenopathy, no heterophile Antibodies
CMV clinical features in Immunocompromised pt.
In HIV , transplant patients
CMV Chorioretinitis
CMV is most common opportunistic infection or virus in HIV and transplant
Cytopathic effect or Inclusion bodies seen in case of CMV Infection
Owl eye appearance (both I/n and I/c inclusions)
CMV virus isolation is done on which cell line
Human Fibroblast cell line (2° cell line)
Antigen found in case of CMV Infection
PP65
Treatment of CMV infection
DOC - Ganciclovir
If Resistance - Foscarnet
HHV 6 Variants
6A
6B
Mode of infection in HHV 6
Oral Secretions
HHV 6 in children causes
Sixth disease/Roseola infantum/Exanthem subitum
Clinical features of Sixth disease/Roseola infantum/Exanthem subitum
Fever
Nagayama spots - erythematous spots on soft palate and uvula
Rash after fever - Rose pink non pruritus papules
HHV 6 known to cause in adults
Mononucleosis like Syndrome
HHV 8 is associated with which diseases
Kaposi sarcoma
Primary Effusion Lymphoma
Castlemann disease (LN)
Kaposi sarcoma
Vascular tumor
M/C associated with immunocompromised status
M/C site - Skin of lower limb
2nd M/C - Lymph node
