Enteroviruses

Question 1

name the picornaviruses

structure/genome?

Answer 1

hepatitis A

rhinovirus

enterovirus(polio/non-polio)

small, naked ssRNA(+)

Question 2

enterovirus transmission in general?

Answer 2

fecal-oral, resp. droplets, fomites

Question 3

seasonality for enteroviruses?

Answer 3

summer/autumn

likes tropical/warm climates

Question 4

describe the general pathogenesis of enteroviruses

Answer 4

1. enter through respiratory tract/esophagus
2. replicate in pharynx/intestine regional lymph nodes days 0-3
3. move to blood(minor viremia) days 3-7; minor hillness
   
   1. goes to reticuloendothelial
4. major viremia days 7-21; major illness
   
   1. goes to target organ(skin/mucosa, muscle, heart, brain, meninges)

Question 5

poliovirus has tropism for what tissue?

Answer 5

CNS

specifically, the anterior horn of the spinal cord

can attack other locations, further defining how the disease manifests

Question 6

describe the progression of paralytic polio infection

how else can polio resolve if non-paralytic

Answer 6

can be asymptomatic, non-specific, aseptic meningitis OR progress to paralytic polio

Clinical manifestation of paralyticpolio: biphasic

1. Minor illness at first
2. high fever, intense myalgia, loss of deep tendon reflex
   
   • Sudden onset of asymmetric paralysis or paresis
   • Max weakness @ day 5
   • Proximal>distal; lower>upper

Question 7

describe the polio vaccines

Answer 7

Inactivated polio Vaccine(IPV) - Salk, 1955 - killed

• Great systemic immunity, can be combined, effective in tropics
• Injection only, less local immunity

Oral Polio Vaccine(OPV) - Sabin, 1961 - live attenuated

• Great systemic and local, easy to give, well accepted
• CAN MUTATE AND CAUSE PARALYSIS; don’t use in US anymore

Question 8

factors that affect the spread of polio

Answer 8

Warm weather favors the spread of disease through contact between individuals participating in water activities. Factors that affect spread include crowding, hygiene, and water quality

Question 9

non-polio enteroviruses

Answer 9

d enteroviruses

coxsackie

echovirus

Question 10

skin/mucosal manifestations of non-polio enteroviruses

Answer 10

Herpangina/stomatitis

• painful vesicles on soft palate/pharynx
• fever, HA, sore throat

**Hand-foot-mouth disease **

• vesicular stomatitis
• vesicles/papules on hands, feet, groin; painful
• fever, HA, sore throat

Question 11

most common cause of community acquired aseptic meningitis?

Answer 11

enteroviruses

all of them can cause it

Question 12

CNS infections involving non-polio enteroviruses

Answer 12

aseptic meningitis

encephalitis

poliomyelitis-like syndrome

Question 13

muscle manifestations of non-polio enteroviruses

Answer 13

pleurodynia - inflammation of chest wall; fever; spasmotic chest pain

myositis - fever, chills, muscle pain(thighs); myoglobinuria/emia

myocarditis - inflammation of pericarditis; necrosis/inflammation; dilated cardiomyopathy due to fibrous recovery

Question 14

eye manifestation of non-polio enteroviruses

Answer 14

**acute hemorrhagic conjunctivitis **

• shed in tears; highly contagious
• hemorrhages under conjunctiva
• eye pain/photophobia

Question 15

manifestation of neonatal infections of non-polio enteroviruses

Answer 15

mimics sepsis

multi-system

often fatal

Question 16

systems potentially infected by non-polio enteroviruses

Answer 16

skin/mucosa

CNS

muscle

eye

BABY SYSTEM(neonates)