Major DNA Viruses Flashcards
Describe the characteristics of Parvovirus: B19.
ss
linear DNA
naked
icosahedral
How is parvovirus transmitted?
respiratory
oral secretions
What is the pathogenesis of parvovirus B19?
infects mitotically active erythroid precursor cells in bone marrow
2-phase disease
- lytic: viremia, flu-like symptoms, viral shedding
- non-infectious immune response
What are the clinical manifestations of parvo?
“slap cheek”
erythematous
lacy reticular maculopapular rash
What are complications of parvovirus B19?
intrauterine infection may lead to hydrops fetalis
Describe the characteristics of Adenovirus.
ds
non-enveloped
linear
DNA
How are adenoviruses transmitted?
*Respiratory
- inhalation of respiratory droplets
- across eye by direct contact
GI
-fecal-oral route
What is the pathogenesis of adenoviruses?
- infect mucoepithelium in tissues
- infect adenoids, tonsils, respiratory epithelium, Peyer’s patches, intestinal epitheia
Which Ig is involved to resolve adenovirus?
IgG
Adenovirus proteins interfere with immune defenses by blocking ?
IFN
T-cells
Adenovirus has what oncogenes?
promote cell growth
EIA »_space; inactivates pRB (retinoblastoma)
E1B» inactivates p53
What are the clinical syndromes of Adenovirus infection?
Acute Febrile Pharyngitis Pharyngoconjunctival fever Acute respiratory disease Other: laryngitis, croup, brionchiolitis Epidemic karatoconjunctivitis "shipyard eye" cervititis, urethritis Acute gastroenteritis (infants)
What are the characteristics of papillomaviridae (HPV)?
ds
non-enveloped
circular
small
What is the incubation period for papillomaviridae (HPV)?
2 weeks to 1+ years
What are common diseases of papillomaviridae (HPV)?
plantar warts anogenital warts (HPV 6/11) Cervical cancer (HPV16/18)
What layer of the skin does papillomaviridae (HPV) develop?
basal cells of the dermal layer via L1 VAP/integrins
What are epithelial spikes referred to as?
papillomatosis
In what layer are prickle cells present? prickle layer?
stratum spinosum
stratum granulosum
In papillomaviridae (HPV), E6 binds to ___________ and activates ___________ and suppresses ____________.
p53
activates telomerase
suppresses apoptosis
in papillomaviridae (HPV) E7 binds to ___.
p105RB
What laboratory tests would you use to diagnose papillomaviridae (HPV)?
Cytology: Koilocytotic cells
In situ DNA probe analysis
PCR
What is the treatment of papillomaviridae (HPV)?
removal
- cryotherapy, electrocautery
- interferon, imiquimod or stripping with duct tape
What vaccinations are available for papillomaviridae (HPV)?
Gardasil (tetravalent HPV6,11,16,18)
Cervarix (divalent HPV16,18)
9-26 years of age
3 doses (initial, 2 mos, 6 mos)
What are the characteristics of herpesvirus (HSV, VZV)?
ds
enveloped
linear
large
How is herpesvirus (HSV, VZV) transmitted?
requires inoculation of virus-containing body fluids
sites: oral, ocular, genital, mucosa, respiratory tract, blood stream
What are the clinical presentations of HSV-1?
lesions on oropharynx
cold sores
fever blisters
What are the clinical presentation of HSV-2?
lesions on genitalia
can be spread without genital lesions
Where do herpesvirus (HSV, VZV) go latent?
nerve ganglia
How are HSV 1/2 transmitted?
close contact
STD
How is VZV transmitted?
respiratory
close contact
What are primary manifestation of HSV-1?
gingiovostomatitis - children(fever, malaise, lesions)
pharyngitis or tonsillitis - adults
What are secondary/recurrent manifestations of HSV-1?
cold sore
keratoconjunctivitis (eye)
Herpetic Gladiatorium
Herpatic Whitlow (fingers)
What are 3 separate phases of HSV?
establishment
maintenance
reactivation
What triggers can reactivate HSV?
stress UV light infection menstruation decreased immunity
How is recurrence suppressed for HSV?
strong cellular immune response
HSV-1 can be responsible for (encephalitis/meningitis)?
encephalitis
What are some HSV complications?
perinatal transmission
encephalitis
meningitis
(if immune suppressed - pneumonia, mucocutaneous lesions)
How would you diagnose HSV 1/2?
clinical appearance
PCR of CSF for HSV encephalitis
Why is HSV difficult to prevent?
many people shed asymptomatically
What is the treatment for HSV?
valacyclovir
acyclovir
famciclovir
In what form is VZV reactivated?
shingles
What can trigger VZV reactivation?
old age
decreased immunity
local injury
How would shingles present?
acute pain
redness of dermatome
rash
post-herpatic neuralgia (PHN) can be prolonged
How would you diagnose VZV?
clinical presentation 3 types of lesions simultaneously - maculopapular - vesicular - scabs
What treatments are available for VZV?
chicken pox - symptomatic
Zoster rash - acyclovir
Zoster PHN - tricycle antidepressant
What are the characteristics of poxviridae?
ds DNA
linear
complex symmetry
cytoplasmic replication
How is poxviridae transmitted?
respiratory droplets
fomites
How does poxviridae present?
basophilic inclusion bodies
What treatments are available for poxviridae?
freezing
electric cautery
chemical agents
What are the characteristics of Hepadnaviridae (HBV)?
ds (partially)
enveloped
circular DNA
How is Hepadnaviridae (HBV) transmitted?
***minute amount can transmit*** blood bodily fluids perinatal (during birth or through milk) (once it enters bloodstream it travels to the liver to infect hepatocytes)
Describe replication of Hepadnaviridae (HBV)?
DNA virus but includes RNA intermediate
encodes reverse transcriptase (RNAd-DNA pol)
What are the clinical manifestations of Hepadnaviridae (HBV)?
hepatitis
excretion of bile pigments
-bilirubin accumulation (Jaundice)
During which phase of chronic HBV would treatment be an option?
immune active
not indicated during immune tolerant or inactive phase
What are the treatment options for Hepadnaviridae (HBV)?
Active vaccine (0,1,6 mos)
Post: supportive HBV immunoglobin (HBIG) IFNa Lamivudine
How would you diagnose Hepadnaviridae (HBV)?
liver function test (ALT>AST)
Jaundice (30%)
RUG discomfort
Antibody detection
