Flashcards in Major DNA viruses Deck (103)
only human parvovirus
ss, linear DNA, naked icosahedral
causes Fifth's disease - slapped cheek rash
Trans: respiratory and oral secretion
What sort of cells does B19 preferentially infect?
mitotically active erythroid precursor cells in the bone marrow
Describe the lytic phase of B19
viremia is established
viral shedding, moves out of bone marrow
flu like symptoms
Describe the non infections immune response of B19
circulating immune complexes that cannot fix complement results in erythematous, maculopapular rash, arthralgia, arthritis (last two rare)
What is important for clearing B19?
what causes common rash illness in school aged children?
lacy reticular maculopapular rash on trunk and extremities
Rash appears with IgM
what is the concern with a B19 infection in a sickle cell patient?
Aplastic crisis - drop in RBCs
concerns with Intrauterine infection of B19
hydrops fetalis or fetal death
Rash appears with IgM
How would you treat acute vs. chronic B19?
since mild - acute treat with supportive care, ibuprofen for fever and topical anesthetic or antihistamine
For chronic which can be seen in IC pts - IV immunoglobins
DsDNA - linear
respiratory trans. via inhalation of droplets or eye contact
GI trans. - fecal-oral route
Pathogenesis of Adenovirus
typically infects where comes in contact with mucoepithelium
commonly infects local lymphoid tissue - conjunctiva, adenoids, tonsils, respiratory, peyer's patches
*typically not pathogenic
Where can Adenovirus persist?
in tonsils and adenoids in childern
in intestines in adults
How does Adenovirus interfere with host defenses?
interferes by blocking IFN and T cells
Viral oncogenes of Adenovirus
lytic in nature so tumorgenesis is not concern
late proteins E1A and E1B leads to cell growth
E1A inactivates pRB (retinoblasts)
E1B inactivates p53 (mediates cell apoptosis)
What are some clinical manifestations of Adenovirus
Acute febrile pharyngitis
Acute respiratory disease
cold, laryngitis, croup, bronchiolitis, viral pneumonia
"shipyard eye" -epidemic keratoconjunctivitis
cervicitis and urethritis - rare in women
acute gastroenteritis in infants
With Adenovirus infections in childern, what symptoms would you see in infants and young children versus older children?
infants and young - acute febrile - stuffy nose, fever, sore throat
Older children - Pharyngoconjunctival fever - tends to occur in outbreaks. associated with underchlorinated pools
Notice lots of military recruits have Acute respiratory disease. Symptoms include fever, runny nose, cough and pharyngitis. A couple of infected recruits also present with conjunctivitis. What could it be?
small, circular (so has own polymerase to make DNA but use host polymerase for RNA), in nucleus, ds, non enveloped
squamous epithelial growth
HPV encodes proteins that promote
lytic infections in permissive cells
transforming, oncogenic infection in non permissive cells
What does HPV cause?
warts, condylomas, papillomas and cervical carcinomas
How long could HPV incubate?
2 weeks to 1 year
what strains of HPV could cause Anogenital warts?
6 and 11
what strains of HPV could cause Cervical carcinomaL?
16 and 18
HPV protein E1
binds DNA at ori and promotes viral DNA replication and has helicase activity