L82 Flashcards

1
Q

Are picorna viruses RNA or DNA?

A

“I went to a retro toga party, drank flavored Coronas, and ate hippy Cali pickles”

Pickles = picorna = +ssRNA

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2
Q

Mnemonic for picorna viruses

A
PERCH
Polio
Echo
Rhino
Coxsackie 
Hep A (acute viral hepatitis)
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3
Q

Picorna

  • Enveloped? –> How released from cells?
  • Where replicate?
A

Naked - released by lysis

RNA - replicate in cytoplasm

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4
Q

Enterovirus is an umbrella term - how so?

A

Enteroviruses split into 2 categories

  • Polio
  • Non-polio = coxsackie & echo viruses & enteroviruses
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5
Q

Enterovirus transmission

A

P2P via fecal-oral
Respiratory
AKA low inoculum needed to create disease

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6
Q

Enterovirus season

A

Summer –> fall

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7
Q

Enterovirus pathogenesis

A

Ingest particles = fecal-oral
Inhale particles = resp droplets
Replicate in mouth/throat or intestines –> invade –> LN –> 1ary viremia minor viremia –> tropic organs
If est infection in tropic organs, give rise to 2ary viremia

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8
Q

Why is the 1ary viremia from enteroviruses not generally clinically significant?

A

1ary viremia = minor

Often controlled by Ab

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9
Q

What is distinguishable about the enteroviruses from other picorna viruses?

A

Resist harsh environments - low pH, detergents, sewage

Allows for oral-fecal transmission!!

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10
Q

When would you see a 2ary viremia from enteroviruses?

A

If disease est sizable replication and infection in tropic organs –> leave these organs back in circulation = 2ary viremia
Means Abs were not present or failed to contain 1ary viremia

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11
Q

Is damage from enteroviruses due to the bug or immune response?

A

Mostly bug - lysis release = cell damage

Host immune response causes myocarditis & rash specifically

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12
Q

What is polio’s tissue tropism? (aka where does it go during 1ary viremia?)

A

Brain
Meninges
Ant horn spinal cord

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13
Q

What kind of paralysis does polio cause?

A
Flaccid
Asymmetric 
Intact sensory neurons 
Proximal before distal
Lower before upper extremities
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14
Q

Why is polio described as biphasic?

A

1st = minor illness = fever, muscle pain, lose deep tendon reflexes
2nd = SUDDEN onset paralysis
Max weakness within 5 days

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15
Q

What disease is caused by polio’s tropism for the meninges?

A

Aseptic meningitis

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16
Q

Diagnose meningitis

A

Clinical + culture ASAP

17
Q

What is the difference between the oral and the injected polio vaccines?

A
Oral = live, don't us in US b/c can mutate to cause disease
Injected = inactivated, lifelong immunity
18
Q

Where is polio still a problem in the world?

A

Pakistan

Afghanistan

19
Q

Why are we switching from a trivalent –> bivalent injectable vaccine?

A

Remove polio serotype 2 - most likely to reactivate to active disease + not seen in wild anymore
Plus vaccines with fewer strains are more immunogenic

20
Q

What is herpangina/stomatitis? What virus causes this?

A

Enanthem = painful mouth blisters
+ fever
Coxsackie A

21
Q

What is hand-foot-mouth disease? What viruses cause this?

A
Blisters in mouth, hands, feet
Sometimes on butt/groin
\+ fever
Cox A & B
Enterovirus 71
22
Q

What is the difference between coxsackie groups A & B?

A

A: does not grow well in culture
B: grows well

23
Q

What 3 CNS infections can non-polio enteroviruses cause? Name the most likely viral cause of each.

A
  1. Aseptic meningitis - all of the viruses can do this, and overall this group of viruses is the most common reason for aseptic meningitis across the board
  2. Encephalitis - Cox A (Entero 71 outbreak)
  3. Polio-myelitis-like illness : N/A
    Guillain-Barre or acute transverse myelitis possible
24
Q

What on a CSF culture makes you think aseptic meningitis?

A

Normal glucose & proteins
Negative gram stain… duh
Hugh white count

25
Q

What is pleurodynia? What virus causes this?

A

= Inflam of chest & ab wall muscles (skeletal muscle)
“I have sharp pain in my chest/ab”
Cox B

26
Q

What is myositis? What is the viral cause?

A

Generalized muscle pain, fever, chills
+ peeing muscle protein (myoglobin)
+ ↑muscle enzymes
Cox B

27
Q

How can non-polio enteroviruses affect the heart?

A

Myocarditis

28
Q

How can non-polio enteroviruses affect the eyes? Explain disease + most common viral cause.

A

Acute hemorrhagic conjunctivitis
- SUPER contagious via tears/touching
- Blood shot eyes + pain
Cox A & enterovirus 70

29
Q

If a neonate presents with a non-polio enterovirus infection, what are the symptoms? How did this baby get sick? Viral cause.

A

Vertical transmitted from mom
Sick in 1st week of life
Looks like SEPSIS: myocarditis, encephalitis, hepatitis, pna
ECHO or Cox B

30
Q

Diagnose non-polio enterovirus infection

A

Culture from invasive infection site
Serum Abs
PCR

31
Q

Treat non-polio enterovirus infections

A

All experimental
Myocarditis = IVIG
Others = oxadiazoles
- Block viral attachment and uncoating

32
Q

What meds do you NEVER give for enterovirus infections because outcomes are worse?

A

Steroids!!!