Negative Sense (-)RNA Viruses Flashcards

1
Q

What is the difference between antigenic drift and shift?

A

Antigenic Drift – point mutations
Antigenic Shift – segments change from reassortment when multiple strains are together in a host (Much worse for pandemics)

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2
Q

What are orthomyxoviruses and their classifications?

A

ss(-)RNA Viruses, 8-segment genome
– Influenza Viruses
Remember – has to bring machinery with it to convert (-)RNA into functional +RNA
–Replicate in the Nucleus

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3
Q

What are the proteins responsible for the pathology of influenza?

A

Hemagluttinin – binds sialic acid in Upper resp tract
M2 Protein – influxes acid to uncoat the virus
Neuraminadase – cleaves the sialic acid to release the virions from the infected cell

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4
Q

What pathway is being blocked by Oseltamivir and Anamivir?

A

– Neuraminadase, releasing of the virions is prevented

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5
Q

What are complications of being infected with influenza?

A

Due to destruction of respiratory epithelial increases risk for bacterial infection – most commonly Strep/Staph

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6
Q

What viruses are apart of the paramyxovirus family and their characteristics?

A

(-)ssRNA, encapsulated

    • Rubeola
    • Mumps
    • RSV
    • Parainfluenza Virus
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7
Q

What are the unique clinical manifestations of Rubeola(Measles)?

A

– Cough
– Conjunctivitis
– Coryza (Runny Nose)
– Fever x4 days
*Koplik Spots in the buccal mucosa
Macular Rash – starts on the face and moves down the body.

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8
Q

What are complications that can arise from measles (Rubeola) infection?

A
  • -Pneumonia

- - subacute sclerosing panencephalitis –from chronic (generally immigrant and personality change)

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9
Q

What can be given to someone with measles to reduce the mortality of children?

A

Vitamin A

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10
Q

What virus can cause parotitis and orchitis?

A

Mumps – can cause sterility and aseptic meningitis

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11
Q

What virus most commonly causes croup and what is the most indicative finding?

A

Parainfluenza Virus

    • upper airway stridor
    • Steeple Sign
  • *Croup = laryngotracheobronchitis
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12
Q

What is the most common cause of pneumonia and bronchiolitis in infants?

A

RSV – less than 6months, binds to resp epithelium via G-protein

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13
Q

How can you classify Rhabdovirus (Rabies)?

A

(-)ssRNA, enveloped helical capsid

  • *Bullet Shaped**
  • -Nigri Bodies (intracellular inclusions)
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14
Q

Who are at risk for Rabies?

A

– exposure to bats/caves, possible rabid other animals

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15
Q

What is the pathology of Rabies virus and symptoms?

A

Initially affects the motor-end plate, but binds Nicotinic Acetylcholine Receptors (motor neurons) and progresses retrograde into the CNS/dorsal root ganglia.

    • Hippocampus / Purkinje cells
    • agitation, photophobia, hydrophobia, esophogeal spasms, death
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16
Q

What classification is ebola / marburg virus?

A

Filovirus – (-)ssRNA

17
Q

What are clinical symptoms of Filovirus and who is at risk?

A
  • Flu-like syndrome, petechiae rash, hemorrhagic fever, hypovolemic shock, death
    • Africans / Healthcare Workers
18
Q

What is unique about Reovirus, compared to other RNA viruses?

A

DOUBLE STRANDED RNA, naked

– Rotovirus

19
Q

What virus causes villous atrophy, watery secretory diarrhea, in children who are in daycare?

A
Rotovirus
-- NSP4 Toxin -- induces the secretion 
-- #1 cause of severe diarrhea in children, should get vaccinated
-- only supportive treatment
RISK for Intussuception
20
Q

What class of viruses have (-)ssRNA segmented and circular and enveloped, that is typically vector bourne?

A

Bunyavirus

    • Arbovirus
    • Hantavirus
    • Rift Valey Fever / California Encephalitis
21
Q

What are common syndrome from Hanta Virus?

A
    • from deer mice
    • Pulmonary Capillary Leak, pre-renal azotemia from fluid loss
  • -pneumonia
    • hemorrhagic fever
22
Q

What is the vector of Rift Valley Fever / California Encephalitis?

A

Aedes Mosquito

– seizures and encephalitis

23
Q

What the causative agent that is responsible for lymphocytic choriomeningitis, how is it unique?

A

Arenavirus – Ambisense (-/+)RNA, 2 segments each is different

    • grainy on microscopy
    • from rodent
    • treat with heating and irradication