DNA viruses Flashcards
Classification of DNA virus Herpesviridae
HHV 1- HSV1
HHV 2- HSV 2
HHV 3- HZV- Chickenpox, Shingles
HHV 4- Epstein Barr virus
HHV 5- Cytomegalovirus (largest member)
HHV 6
HHV 7
HHV 8
Where do HSV-1 and HSV-2 establish latency?
HSV-1 → Trigeminal ganglion
HSV-2 → Sacral ganglion
How is HSV transmitted?
HSV-1: Saliva, respiratory secretions
HSV-2: Sexual contact, perinatal transmission
Neonatal herpes is caused by
HSV 2
Neurovirulence in HSV is caused more by
HSV 2
MC CNS infection by HSV 1
MC primary HSV 1 lesion
MC recurrent HSV 1 lesion
- Gingivostomatitis
- Herpes labialis
Mollaret’s meningitis
Recurrent Lymphocytic meningitis.
Caused by HSV 2
Tzanck smear
1. For which organism?
2. What is the cytopathic effect seen?
3. ___ bodies are seen
- HSV
- Margination, moulding, multinucleated
- Lipshultz bodies
Tx for HSV
Acyclovir
If Resistance: Foscarnet
Painless ulcers are seen with
Syphillis
LGV (painful buboes)
Klebsiella granulomatosis
IP of VZV
2-3 weeks
Rash distribution of VZV
B/L diffuse centrifugal distribution- starts on trunk, moves outward
MC complication of VZV infection
MC extracutaneous complication
Most serious complication
- Secondary bacterial infection
- CNS infection- benign cerebellar ataxia
- Varicella pneumonia (esp in pregnancy)
Fetal congenital varicella syndrome
Within 20 wks IUL
Features:
Microcephaly
Cortical atrophy
Cicatricial skin lesion
Limb hypoplasia
Rash distribution for HZV
U/L
Segmental because of dermatomal distribution (MC D3 to L2)
MC complication of HZV
Post herpetic neuralgia
Ramsay Hunt syndrome involves?
What are the clinical features?
Geniculate ganglion of CN VII
Vesicles at EAM, Otalgia
Loss of taste at ant 2/3 of tongue
Epstein Barr Virus causes ______ cell activation. It enters cell through _____. It has the following molecules:
Polyclonal B cell
CD21/ Cr2
LMP 1 (acts on CD40 pathway)
EBNA2 (activates SRC proto-oncogenes)
vIL10
Clinical features of Infectious mononucleosis
Caused by EBV
IP: 4-8 weeks
Called Kissing disease/ Glandular fever
Splenomegaly, hepatitis
Encephalitis, LN
Sore throat, fever, arthralgia, lethargy
Malignancy associated with EBV
MC- Gastric Ca
Nasopharyngeal Ca
Leiomyosarcoma
Lymphoma-
Hodgkins (Mixed cellularity type)
Non Hodgkins (Burkitt’s, DLBCL, Post transplant lymphoma, T/NK cell lymphoma)
Other conditions associated with EBV
Duncan syndrome- lymphoproliferative d/s
Hairy cell leukoplakia/ Oral cell leukoplakia
Hemophagocytic Lymphohistiocytosis
Microscopic feature of EBV
Atypical lymphocytes- Downey cells- composed of CD8 T cells. AKA Ballerina skirt appearance
Diagnosis of EBV
Heterophile Antibody test- Paul Bunnell test (old), Monospot test (new)
Specific antibody test- Ab to viral capsid antigen, to early antigen, to EBNA
Treatment to EBV
Acyclovir (for Oral hairy leukoplakia)
Rituximab
Reservoir of CMV
Man is the only reservoir
Transmission of CMV
Oral, respiratory, body secretions.
Transplacental
sexual
CMV multiplies in
Salivary gland
Resp tract
Kidney
CMV is latent in
Monocyte
MC IU infection asso with congenital defects
CMV infection
Symptoms of CMV infection
MC symptoms:
HSM
Purpuric rashes (Blueberry muffin baby)
Jaundice
Other: Microcephaly, Chorioretinitis, Deafness, Periventricular calcification
CMV manifestation in
1. Perinatal period
2. Immunocompromised
3. Immunocompetent
- Asymptomatic
- CMV chorioretinitis
- Glandular fever like disease- fever, sore throat, no LN, no antibodies, no spleen
MC opportunistic viral infection in HIV/ transplantation patients
CMV chorioretinitis
Lab diagnosis of CMV
- Inclusion bodies- Owl eye app; intranuclear and intracytoplasmic inclusions
- Antigen: Pp65
- Virus isolation: Human Fibroblast cell line; specimen: urine washing
- Antibody detection by ELISA
- PCR
Treatment for CMV
DOC: Ganciclovir. If resistant- Foscarnet
HHV 6 causes
Sixth disease/ roseola infantum/ exanthem subitum
HHV 6 binds to T cells via
CD 46 receptor
variants of HHV 6
6A, 6B
Features of HHV 6 infection in children vs adults
Child: fever, rash after fever, non pruritic, Nagayama spots
Adults: Mononucleosis like illness
HHV 8 causes
- Kaposi sarcoma
- Primary effusion lymphoma
- Castleman’s d/s
Kaposi sarcoma Mc asso with ____. MC site is ____ and 2nd MC site is _____
HIV
Lower limb skin
LN
Primary effusion lymphoma
Pt has lots of effusions- pleural effusion, pericardial effusion
CD30 and CD38 +
Castleman d/s
In LN
Onion skinning of lymphocytes
Lollipop follicles
Fever, night sweats, wt loss
Smallest virus
Parvovirus
Only DNA virus to have single strand
Parvovirus
Spread of Parvovirus
Respiratory route
Blood transfusion
Transplacental
MOA of Parvovirus
Attacks P antigen of RBC
PArvovirus causes
Erythema infectiosum/ Slapped cheek appearance/ 5th disease
Symptoms of erythema infectiosum
Glove and socks syndrome
Arthritis, Arthralgia
Other conditions caused by Parvovirus B19
Aplastic crisis in Hemolytic anemia (vs hemolytic crisis in EBV infection)
Pure red cell aplasia a/w thymoma
Hydrops fetalis
Polyoma viruses include
Merkel cell virus
BK virus
SV 40 virus
JC virus
Merkel cell virus causes
Merkel cell ca which is a neuroendocrine tumor of the skin
SV 40 virus is a/w
Mesothelioma
JC virus causes
Progressive Multifocal leucoencephalopathy (PMLE)
JC virus attacks oligodendrocytes
BK virus causes
infection in post kidney transplant patients
Urine will have Decoy cells (which mimic malignancy)
HPV cutaneous involvement
HPV 1, 2, 3 (low risk)- shows skin warts
HPV 5,8 (high risk)- treeman syndrome/ Epidermodysplasia verruciformis (a/w ch 17 defect)
HPV mucosal involvement
HPV 6, 11- mucosal warts, condyloma acuminatum
HPV 16, 18, 31, 33, 35 (high risk). causes SCC of penile, anal, oral, cervical, esophageal.
_____ protein of HPV is used to make vaccine
L1 capsid
___ protein is the controller of HPV
___ protein is responsible for Koilocytosis
_____ protein is responsible for carcinogenesis
E1
E4, E5
E6, E7
___ protein inactivates p53 in HPV
___ protein inactivates RB gene in HPV
E6
E7
Diseases caused by Adenovirus
Hemorrhagic cystitis
Infant diarrhoea
Epidemic keratoconjunctivitis/ Shipyard eye
Pharyngoconjunctival fever/ swimming pool conjunctivitis
URTI, Pneumonia
In transplant recipients
Which hepatitis virus is a DNA virus?
HEP B
Rest are RNA viruses
Families of Hepatitis viruses
‘Private Hospitals Favor Rich Clients’
Hep A- Picornaviridae
Hep B- Hepadnaviridae
Hep C- Flaviviridae
Hep D- Relies on HBV
Hep E- Calicivirus (now Hepeviridae)
Which Hep viruses spread via Feco oral route?
HAV, HEV
Which Hep virus spreads via parenteral route?
Hep B, Hep C
Which Hep virus spreads via sexual route?
Hep B
Mother to Child transmission is seen in which hep virus?
HBA
Which Hep viruses are enveloped?
B, C, D
Which Hep virus is cultivable?
Hep A
Which Hep virus doesn’t have vaccines against them?
C
Bc it follows quasispecies- mutates when a vaccine is made for a variant
MCC of Fulminant hepatitis
Hep D
Chronicity is seen in which Hep virus?
B and C
Carrier state is seen in which Hep virus?
B