Important ocular viruses Flashcards
(30 cards)
What are examples of DNA viruses?
Herpes virus:
HSV
VZV
CMZ
EBV
Adenovirus (dsDNA)
Papovavirus HPV
Pox virus
What are examples of RNA viruses
Paramyxovirus - measles, mumps
Togavirus - rubella (ss)
Retrovirus
HTLV
HIV (Ss)
Orthovirus
Influenza
Picronavirus
Coxsackie
Structure of herpes virus
DS DNA
Icosahedral capsid
What are 4 herpes viruses
HSV
VZV
CMV
EBV
What are features of congenital CMV infection
Strabismus
Chorioretinitis
Microphthalmia
Childhood hepatitis
Post transfusion mononucleosis
What is rsik fo EBV?
TRansfor B lymphoblasts and associated with Burkitt’s lymphoma and nasopharyngeal carcinoma
What is adenovirus?
dsDNA
IScahedral capsid
No envelope
What is HPV
dsDNA
DNA arranged into circle molecule
Infects epithelial cells
What HPV are associated with benign conjunctival papilloma?
6 and 11
What HPV are associated with cancer
16 and 18
E2 gene regulates HPV, disruption of this gene results in production of E6 which forms complex with p53 TSG - oncogeneisis
What are pox virsues? What do they cause?
DNA virus grown in cytoplasm
Contain enzymes that allow replication independent of host cell
Molluscum contagiosum
What is rubella?
What congential defects occur with rubella?
Single stranded RNA virus - togavirs
Cataract
Microphthalmia
Salt and pepper retinitis
Glaucoma
Conductive deafness
EHar defects
What is measles?
What congential defects occur with measles?
Single stranded RNA virus - paramyxoviridae
Keratitis
Conjucntivitis
Cataract
ONH drusen
Diffuse pigmentary retinapthy
What is subacute sclerosin pancencephalitis
Late complication of acquired measles infection
6-8 years after infection
Memory, behaviour, visula impairment
Death in 1-3 years
Focal reitnitis
Papilloedema
Minimal vitritis
Raised IgG in plasma/CSF
EEG abnormality
What are oclular complications of mumps?
Dacroadenitis
EOM palsy
What are human T cell lymphotrophic viruses assocaited with?
T cell lymphoma
Progresive myelopathy
Uveitis in some ethnic groupsCa
What is HTLV uveitis more common in
Japanese
African
What genes regulate HTLV1 replciation
Tax and rex
What cells does HIV infect
CD4
Structure of HIV
Single strand RNA with reverse transcriptase
What genes does HIV have?
Structural genes - envelope gene codes for glucoprotein enclosing viral particle
REgulatory genes - stimualte viral transcription and cause proliferation of adjacent healthy cells e.g. B cells and Kaposi sarcoma
Polymerase gene - for reverse trascriptase - creates DNA molecule from viral RNA - inc in human genome
How can HIV be killed?
Strong acid and alkali (pH < 1 or >13)
Exposure to 10% bleach
50% ethanol
How does HIV affect the immune system?
Binds to CD4 antigen and CXC chemokine receptors on CD4 cells
Leads to formation of a multinucleate cell and cell death
Cell mediated immune response diminished
Predisposed to infection and neoplasm
Latent virus is invisible to immune defences and mutates rapidly by antigenic shift
When does HIV seroconversion occur?
4-12 weeks after acute infection
