Major DNA Viruses Flashcards
SsDNA naked, icosahedral
Parvovirus
Determinant for B19 tropism
Erythrocyte P antigen
acts as a receptor
____ a type of glycoshpingolipid on RBC
Globoside
When does parvovirus replicate
When host cell is in S phase
Why does B19 not attack RBC
Because they don’t have a nucleus
So they attach erythroblasts
B19 arthritis is from
Immune complex mediated
Most common age group fro 5th disease
5-14
Phases of erythema infectious
Phase 1 = infectious stage
Mild fever, sore throat, runny nose
Phase 2 = virus cleared
slapped cheek rash
lacy rash on trunk, arms, legs
Slapped cheek rash is ______
Immune complex mediated
B19 can cross
Placenta
B19 during 1st trimester =
Death
B19 during 2nd =
Hydrops fetalis —-> death
B19 during 3rd trimester
No apparent clinical symptoms
B19 treatment
No treatment unless immunocompromised
if so, maybe transfusion
Leading cause of pharyngitis
Adenovirus
Why does it make sense that adenovirus can have outbreaks in pools
It’s naked and can survive the chlorine in pools
Adenovirus types 4, 7, 14 are associated with
Severe lower resp tract infections
Adenovirus types 40 + 41 associated with
Gastroenteritis; transmitted fecal/orally
Adenovirus types 11 + 21 are associated with
Hemorrhagic cystitis
How would you diagnose adenovirus
Look for increase in antibody titer
PCR for viral sequences
How do you treat adenovirus
Self resolves, you treat the symptoms
Live vax for military recruits
________ for immunocomprimised people with severe adenovirus infection
Cidofovir
Tropism for papilloma
Epithelial cells of skin and mucosa
Papilloma is _____ infection on _____ cells
Lytic
Permissive
Papilloma is _____ infecticions in ______
Transforming
Non permissive
How do you transmit papilloma
Direct contact
Exposure during birth
Sex
Papilloma route of transmission depends on
Serotype
HPV infects _____ cells
Basal
HPV, viral DNA induces cell proliferation and thickening in
Basal layer
Stratum spinous
Stratum granulosum
HPV, mature virion is only on _____ layers of skin
Outermost
How does HPV move on in association with skin
As our skin shed the viral particles get spread
HPV latent vs transforming infections
L = viral DNA is not integrated
T = viral DNA is integrated
E5 = ( of HPV)
Activates EGF, epithelial growth factor
E6 =
Binds and targets p53 for degration
E7 =
Binds and inactivates RB
Verruca vulgaris
Common wart
Where are verruca vulgaris usually
Hands and knees
Verruca plana
Flat warts on hands, face, shins
Plantar warts
Grow into soles of feet
Condyloma acuminata aka
Genital warts
Infected epithelial cells have a clear halo around a shrunken nucleus
Koilocytes
Managing HPV
Could resolve spontaneously
Freeze
Surgically remove
Etc
Preventing HPV
Vax!
Gardasil 9
covers 9 subtypes
6,11,16,18,31,33,45,52,58
When should someone get gardasil
Before they’re sexually active
Starting at 11 years old
___ cells express a capsid protein called ___
Yeast
L1
Polyomaviridae is ____ in immunocompetent people
Asymptomatic
Transmission of polyomavirus
Inhalation
Fecal/oral
Kidneys are a big site of _____ with polyoma virus
Latency
Latent infection of the kidneys =
BK
Latent infection in kidneys, B cells, monocyte lineage cells
JC
Why would polyoma get reactivated
Someone become immunocompromised
Early genes of polyoma virus
T (transformation) antigens
What do T antigens do
Bind and inactive p53 and retinoblastoma protein
Late genes of polyoma virus
Capsid proteins
VP1
VP2
VP3
VP1
Major capsid protein and viral attachment protein
VP2 and VP3
Minor capsid proteins
PML from
JC
Hemorrhagic cystitis from
BK
Or adenovirus
___ can cross bbb and replicates in the endothelial cells of ____
JC
Capillaries
JC ____ infections of oligodendrocytes and astrocytes
Productive Lytic
Subacute demyelinating disease
PML
PML severity
> 90% fatality rate
2-4 months
How do you diagnose polyoma
Urine cytologies tests
Detect gene seq in csf, pee, biopsy material
PML diagnosis
What do you look for in a urine cytologies test for JC/BK
Enlarges cells with dense basophilic intranuclear inclusions consistent with JC/BK
How do you diagnose PML
Histo of brain tissue = demyelination surrounded by oligodend. With inclusions
PCR detects viral DNA in csf
MRI showing lesions
Adenovirus, papilloma, polyoma are all
Naked
dsDNA
Icosahedral
Enveloped icosehedral
Herpes
Alpha herpes primary target cell
What viruses
Epithelial cells
HSV1 - mucoepithelial cells, fibroblasts
HSV2 - mucoeptithelial cells, fibroblasts
VZV - mucoepithelial cells, T cells
Beta viruses primary target cell
What viruses
Variety of cells
CMV - leukocytes, epithelial cells, fibroblasts
HHV6 - lymphocytes
HHV7 - lymphocytes
Gamma viruses primary target cell
What viruses
EBV - B cells and epithelial cells
HSHV - B cells, endothelial cells, epithelial cells, monocytes
Where do alpha sit latent
Neurons
Where do gamma sit latent
B cells
Where to beta sit latent
CMV - monocytes, myeloid stem cells
HHV6 - T cells
HHV7 - T cells
Latency of HSV
Immediate early genes are NOT expressed so non of the early or late viral genes are expressed
LATs are associated with
Replication of HSV
Latency-associated transcripts
How does HSV mainly spread systemically
Traveling within infected leukocytes
VZV, EBV, CMV
LATs inhibit _____ of infected neurons
Apoptosis
LATs inhibit ____ of viral IE genes
Expression
How is replication triggered in a _______ of HSV
Neuron
Sunlight
Fever
Stress
Immunosuppression
What does deactivation look like in HSV
New viral particle travels down the axon to site of initial infection and productively infects epithelial cells
What does reactivation look like in VZV
Reactivation = productive infection in a dermatome enervated by the neuron in which reactivation occurs
HSV1, HSV2, VZV
Transmit by
Saliva
Sex
Hand to mouth
Skin to skin
wrestler, herpetic gladiatorum
HSV and VZV lesions
Vesicles —> ulcer —> crusted lesions
____ in the lesions contains infectious virus in alpha
Fluid
HSV1 or 2 is more common of a genital infection
2
Neonatal herpes usually caused by
HSV2
Where does HSV reactivate vs VZV
H = cold sores, genital lesions
V = Zosters
Where does HSV reactivate vs VZV
H: site of primary infection
V: Site where virus entered neuron
How often does HSV vs VZV reactivate
H: often
V: 1 episode
probability of reactivation of HSV vs VZV
H: decreases with age
V: increases with age
What do you look for in a tzanck smear
Syncytia
Cow dry type A intranuclear inclusion bodies
Serology of HSV vs VZV
H: significant increase in titer may not occur in reactivation
V: antibody tigers do increase in pt with zoster
Prego mamas avoid HSV and VZV by
C section
A kid immunocomprimised doesn’t get VZV vax instead ___ because
They get anti-VZV immunoglobulin
Vax could cause the disease
What is more likely to cause roseola
HHV6
How do you differentiate CMV and EBV
Heterophile antibody negative mononucleosis
CMV is ____ severe than EBV mono
Less
Which mono is it rare to see exudative pharyngitis, CMV or EBV
CMV
How can cytomegalic inclusion disease be reactivated
During pregnancy
Mom has protective antibodies and a healthy newborn BUT there is a prolonged shedding of virus
EBV receptor
CR2/CD21
this is a receptor for C3b
With EBV what is used as a co-receptor
MHC class II
Productive infection of EBV proteins
VCA - viral capsid antigen
EA - early antigen
MA - membrane antigen
Zebra - transcription activator; activates immediate early genes
Non productiveinfection of EBV proteins
EBNAs - Epsetin Barr nuclear antigens
LP - Latent proteins
LMP 1 & 2 - Latent membrane proteins
EBER 1 & 2 - 2 small ep. Barr encoded rna molecules
What indicates previous infection of EBV
Detecting both VCA IgG & EBNA antibodies
See infectious mononucleosis pic
Yub yub
Primary infection of HHV8 in immunocompetent ppl
Asymptomatic
Primary infection of HHV8 in immunocomprimised ppl
Fever, spleen omega lay, lymphoid hyperplasia
Transformation of HHV8
Virus expresses proteins with homologous to cellular proteins that promote growth + inhibit apoptosis
Kaposi sarcoma characteristics
Cancer of lymph endothelial lining
Bluish red cutaneous nodules
Primary effusion lymphoma aka
Body cavity based lymphomas
Multi centric castleman’s disease is what and what is it associated with
lymphoproliferative disease
Fever, splenomegaly, hepatomegaly, generalized lymphadenopathy
HHV8
HBsAG =
Hepatitis B surface Antigen
If you have an antibody to HBsAG =
You have immunity to HBV
HBV is a ____ virus that replicates through an _____
DNA
RNA intermediary
P protein of HBV is what
RNA dependent DNA polymerase with RNase H activity
Gene S of HBV
Surface glycoprotein (HBsAg)
Small medium and large
Gene C of HBV
2 Initiation codons
HBcAg = core protein
HBeAG= secreted protein
What is a marker for high infectivity of HBV
HBeAG
How is HBV transmitted
Sexual, IV drug use, blood, perinatal
Acute infection of HBV signs
Incubates 6 weeks to 6 months
Fever, fatigue, nausea, ab discomfort, DARK URINE, JAUNDICE
Lasts 1-3 weeks
Chronic hepatitis infections signs
HBsAG for more than 6 months
Anti HBC = positive
Anthi HBs = negative
Prevent HBV with
Vax
Managing HBV with
HBV immunoglobulin after exposure
Antiviral drugs
that inhibit rna dependent DNA polymerase
Small pox aka
Variola
Monkey pox and variable name
Orthopoxvirus
Smallpox vax is
Live attenuated
How do you transmit monkey pox
Contact with fluid from lesions
Symptoms of monkey pox
Like small pox but milder
Flu-like symptoms
Lymphadenopathy
Rash
Umbilicated lesion =
Molluscom contagiosum
Molluscum vs chicken pox
M = harder papule than fluid filled chicken pox
M= last for weeks
Chicken = clears up in weeks
