Enteric virus

Question 1

Reovirus virology

• transmission
• human infecting reovirus

Answer 1

Double protein capsid w/ segmented ds-RNA genome

• fecal oral
• rotavirus, orthoreovirus

Question 2

Rotavirus pathogenesis

-target

Answer 2

infection is self-limited but there is a risk of dehydration
- sm. intestine villi

Question 3

Rotavirus presentation

Answer 3

winter months, children < 5 yrs

Question 4

Rotavirus virulence factor

Answer 4

nonstructural protein 4 (NSP4): enterotoxin interfering w/ sodium transport pumps

Question 5

Dx rota on exam

Answer 5

• hx of exposure to other children w/ diarrhea
• NVD
• dehydration,: waterly, bloodless diarrhea w/ decreased urine output

Question 6

Is there a vaccination for rota>

Answer 6

yes but they are not required

Question 7

Norovirus virology

• which virus is the prototypical strain
• transmission

Answer 7

positive-sense ss-RNA virus in Caliciviridae

• norwalk virus
• fecal-oral (highly contagious so you can pick it up anywhere)

Question 8

What makes norwalk virus so contagious

Answer 8

only 100 particles need to establish infection, viral shedding occurs for weeks even after recovery, very environmentally rigid (can survive freezing and boiling), and infect can recur

Question 9

What is the main different between a rotavirus and norovirus infection

Answer 9

rotavirus takes a few days, norovirus strikes quickly and lasts only 1-2 days; also nausea is more common w/ norovirus because it slows gastric emptying

Question 10

What are the common sources of infectious outbreaks

Answer 10

cruise ships, summer camps, nursing homes

Question 11

Picornavirus subtypes (2)

Answer 11

Rhinovirus and enteroviruses

Question 12

picornavirus enterovirus categories (4)

Answer 12

HepA, pilioviruses, coxsackievirus, other

Question 13

enterovirus virology

Answer 13

small naked, icosahedral virions, ssRNA, positive sense

Question 14

enterovirus dual tropism

Answer 14

usually replicate in the gut but sometimes in the CNS

Question 15

enterovirus: Poliovirus

Answer 15

polio

Question 16

enterovirus: coxsackie A

Answer 16

herpangina, hand-foot-mouth disease, acute hemorrhagic conjunctivitis

Question 17

enterovirus: coxsackie B

Answer 17

myocarditis, pleurodynia

Question 18

enterovirus: echoviruses

Answer 18

meningitis, pediatric febrile illness

Question 19

Poliovirus pathogenesis

Answer 19

fecal-oral transmission, uses CD155 receptor to enter and infect the gut, spread to blood and lymphnodes

Question 20

Hows does polio hit the CNS

Answer 20

CD155 found on gray matter CNS cells, crosses BBB or via axonal transport from peripheral nerve

Question 21

where specifically does the polio virus infect in the CNS

Answer 21

anterior horn of motor neurons in the spinal cord

Question 22

Presentation of acute paralytic poliomyelitis

Answer 22

flaccid asymmetric weakness and muscle atrophy due to loss of motor neurons and denervation of their associated skeletal muscles

Question 23

Risk factors for paralytic poliomyelitis

Answer 23

young, old, recent hard exercise, tonsillectomy, pregnancy, immunosuppression

Question 24

Early presentation of paralytic poliomyelitis

Answer 24

severe muslce pain, spasms, weakness (lower limbs more effected than upper)

Question 25

Dx polio

Answer 25

lumbar puncture, culture, MRI (anterior horns)

Question 26

what is Herpangina? when is it most likely to occur

Answer 26

acute febrile illness, small vesicular/ulcerative lesions in the back of the throat and roof of mouth; in the summer in children and young adults

Question 27

hand-foot-and-mouth disease - complications? - most likely causitive agents

Answer 27

spread by fecal oral route w/ skin lesions and oral secretions; symptoms follow viremia/viral invasion of mucus membrane - rarely aseptic meningitis or myocarditis; pneumonitis, pulmonary edema - coxs A, enterovirus 71

Question 28

HFMD pathogenesis | -group at risk

Answer 28

1wk incubation then sore mouth, throat, fever > vesicular eruption in mouth, hands, feet, buttocks, genitalia -children under 10

Question 29

Acute hemorrhagic conjunctivitis | - causative agents

Answer 29

rapid-onset painful conjunctivitis | - coxs A24 and enterovirus E70

Question 30

Viral myocarditis pathogenesis - most common causative agents - who is at highest risk

Answer 30

inflammatory disorder of the myocardium, necrosis of myocytes, infiltrate - adenovirus, enterovirus - infants and pregnant women/ immunocompromised pts

Question 31

In which coxsackie infection presentation do you need to do lab work

Answer 31

myocarditis (CBC, cultures, markers of myocardial damage) and pleurodynia

Question 32

Pleurodynea

Answer 32

sudden occurrence of lancinating chest pain attacks, fever, headache, malaise (pleural friction rub)

Question 33

pleurodynea pathogenesis

Answer 33

striated muscle around the lungs is the target of coxsackie B

Question 34

Aseptic meningitis

Answer 34

viral, not bacterial/fungal.. most rule those out.