Exam 2 - Enteroviruses Flashcards
enteroviruses have a __________ genome
+ssRNA
location of enteroviruses
GI tract (intestines)
enteroviruses shed in _________ for prolonged time
feces
what discovered that a virus caused polio?
Chamberlain filter
why was polio a public concern?
- mysterious, seasonal
- paralyze respiratory muscles
- strange effects
mode of transmission for polio
oral-fecal, oral-oral (rare)
when is polio most infectious?
just before onset and 1-2 weeks after onset
up to 95% of polio infections are ______________
asymptomatic
major illness of polio caused inflammation of _______________, which caused _______________ and ________________
motor neurons, weakened muscles and flaccid paralysis
paralytic poliomyletitis
destruction of motor neurons, paralysis is permanent
what are the 3 forms of major polio illness?
- spinal
- bulbar
- bulbospinal
describe the spinal form of major polio illness
- lower spinal column
- paralysis of legs (asymmetric)
describe the bulbar form of major polio illness
- upper spinal column and medulla
- inability to talk or swallow
- iron lung or respiratory
describe the bulbospinal form of major polio illness
combination of both spinal and bulbar symptoms
what is the main result of major polio illness?
permanent paralysis
post-poliomyelitis syndrome (PPS)
affects a large proportion of those who recovered from major illness
post-poliomyelitis syndrome (PPS) is more common in __________
women
what is the treatment for post-poliomyelitis syndrome (PPS)?
supportive care - pain management, physical and occupational therapy
what is the cause of post-poliomyelitis syndrome (PPS)?
infected motor neurons degenerate and die and surviving neurons degenerate over time
poliovirus enters through the ________
mouth
primary viremia results in ________________, while secondary viremia results in _________________
mild symptoms; major illness
poliovirus is a part of the ______________ family
picornaviridae
structure of poliovirus
naked icosahedral capsid - 4 VPs
steps of poliovirus replication
- poliovirus binds to PV receptor on host cell wall
- endocytosis and uncoating to release viral genome
- production of polyprotein –> proteolytic cleavage –> viral proteins
- production of genome
- assembly
- release by lysis
