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Flashcards in L82 Deck (32):
1

Are picorna viruses RNA or DNA?

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

Pickles = picorna = +ssRNA

2

Mnemonic for picorna viruses

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

3

Picorna
- Enveloped? --> How released from cells?
- Where replicate?

Naked - released by lysis
RNA - replicate in cytoplasm

4

Enterovirus is an umbrella term - how so?

Enteroviruses split into 2 categories
- Polio
- Non-polio = coxsackie & echo viruses & enteroviruses

5

Enterovirus transmission

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

6

Enterovirus season

Summer --> fall

7

Enterovirus pathogenesis

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

8

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

1ary viremia = minor
Often controlled by Ab

9

What is distinguishable about the enteroviruses from other picorna viruses?

Resist harsh environments - low pH, detergents, sewage
Allows for oral-fecal transmission!!

10

When would you see a 2ary viremia from enteroviruses?

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

11

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

Mostly bug - lysis release = cell damage
Host immune response causes myocarditis & rash specifically

12

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

Brain
Meninges
**Ant horn spinal cord**

13

What kind of paralysis does polio cause?

Flaccid
Asymmetric
Intact sensory neurons
Proximal before distal
Lower before upper extremities

14

Why is polio described as biphasic?

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

15

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

Aseptic meningitis

16

Diagnose meningitis

Clinical + culture ASAP

17

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

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

18

Where is polio still a problem in the world?

Pakistan
Afghanistan

19

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

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

What is herpangina/stomatitis? What virus causes this?

Enanthem = painful mouth blisters
+ fever
Coxsackie A

21

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

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

22

What is the difference between coxsackie groups A & B?

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

23

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

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

What on a CSF culture makes you think aseptic meningitis?

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

25

What is pleurodynia? What virus causes this?

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

26

What is myositis? What is the viral cause?

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

27

How can non-polio enteroviruses affect the heart?

Myocarditis

28

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

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

29

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

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

30

Diagnose non-polio enterovirus infection

Culture from invasive infection site
Serum Abs
PCR

31

Treat non-polio enterovirus infections

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

32

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

Steroids!!!