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17 Cards in this Set
- Front
- Back
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Basic stucture of adenoviruses? |
icosahedral, non-enveloped, tough virion, ds DNA genome |
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Replication of adenoviruses? |
uses viral polymerase and assembles in the jewcleus.
host cell RNA polymerase transcribes early viral genes/ splicing occurs
progeny virions released by cell lysis
can cause lytic and persistent infections |
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Diseases caused by adenoviruses? |
*Depends on tissue tropism
acute febrile pharyngitis and pharyngoconjunctival fever
acute respiratory disease
"colds," laryngitis, bronchiolitis, pneumonias, "swimming pool" conjunctivitis
Gastroenteritis and Diarrhea
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Adenovirus transmission? |
aerosol droplets, fecal-oral route, fomites, direct inoculation of conjunctiva |
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Type of immunity after adenovirus infection? |
Both innate and CMI important, IgG leads to long lasting immunity
Many different serotypes lead to different infections |
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How can adenovirus infections be prevented? |
disinfect eating utensils, sanitary disposal of nose and mouth discharges, good personal hygiene, no vaccine currently in use |
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Structure of parvovirus B19? |
small, tough, non-enveloped, icosahedral capsid
ss DNA negative sense genome
B19 only parvovirus causing disease in humans |
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What types of cells does parvo B19 infect? How does it replicate? |
red blood cell precursors and endothelial cells in blood vessels
replication occurs in nucleus of dividing cells
requires host factors and DNA polymerase, release occurs by lysis
cells destroyed by lysis, in some cases pathogenesis due to immune complexes |
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What diseases can B19 cause? |
Erythema infectiosum- acute benign contagious exanthum of childhood (slapped cheek erythema), spreads to trunk and limbs
Infection during pregnancy has been associated with fetal death during the first trimester, hydrops fetalis in 2nd trimester (anemia and CHF).
Aplastic crises and can complicate sickle cell anemia
Polyarthritis in adults (immune mediated) |
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How is B19 transmitted? |
respiratory route, blood transfusion/clotting factors, needles, vertically from mother to fetus
spread is greatest among people in close contact |
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How long does immunity to B19 last? |
obtained after first infection, only one serotype |
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HPV structure? |
small, non-enveloped virion in icosahedral capsid
ds DNA genome |
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Describe replication of HPV |
enters through breaks in skin
highly tropic for epthelial cells, replication cycle depends on differentiated state of epithelial cell
earl viral gene expression stimulates cell division, facilitating viral replication (virus used host DNA pol)
viral assembly occurs in stratum granulosum virus shed with upper layer of dead keratinocytes |
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Diseases associated with papilloma viruses? How are they transmitted? |
transmitted through sexual contact, fomites, passage of child through infected birth canal
causes benign cutaneous warts: common, plantar, and flat warts occur in children and young adults
Head and Neck squamous cell carcinomas; also associated with increased risk of anogenital cancers
Anogenital warts (condylomata acuminata) in sexually active people
HPV-16, -18 can cause cervical cancer
recurrent respiratory papillomatosis |
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How are papilloma viruses treated and how can they be prevented? |
Papanicolaou smears detect papilloma virus infection
no anti virals
treatments include surgical excision, immune modulation, physical or chemical destruction of infected tissue
waiting for resolution without treatment (warts)
prevention:
avoid direct contact, barrier use, vaccination based on virus like particles (non-infectious) |
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Polyomavirus- how are BK and JC viruses transmitted? |
most people infected by 15 years, probably transmitted through respiratory route, maybe fecal oral
infection usually clinically latent, can be activated by immunosuppression
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Diseases caused by BK and JC viruses? |
progressive multifocal leukoencephalopathy: a rare syndrome that occurs in immunocompromised (JC in AIDS patients)
patients with multiple neurological symptoms, impaired speech, vision, coordination, mentation, or combination
can lead to paralysis in arms and legs, death
BK can lead to severe urinary tract infections |
