Case Study Comparison Chart: Polio Flashcards
what is the full name for polio?
poliomyelitis
what is the causative agent of poliomyelitis
polio virus
describe the structure of polio virus (4)
- icosahedral
- ss+RNA (does not package replicase)
- nkd (resists degradation and can withstand stomach acid)
- enterovirus (oral-fecal route)
describe the different stages of a polio infection (4)
- digestive tract
- lymphatic stage
- viremia stage (blood), crosses blood-brain barrier to
- neural stage (CNS)
describe the general distribution (%) of polio symptoms
99% of people are asymptomatic or mild symptoms
1% get paralytic polio
can asymptomatic people transmit polio? if so, how and for how long?
yes. in feces, for 4-6 weeks.
how to detect virus in fecal sample?
direct ELISA test
describe some symptoms of paralytic polio (4 groups)
- muscle weakness (atrophy)
- flaccid paralysis in limbs and chest
- headache, fever, stiffness in neck (inflammation)
- GI symptoms
what happens to an infected motor neuron? why is that significant?
it dies, cutting off the signals to muscles
why is polio hard to study?
- hardy: resistant to degradation
- dangerous. Cutter incident, humans are the only host.
what is one example of why polio is ~dangerous~ to study?
the Cutter incident
what happened in the Cutter incident?
Cutter was a lab that produced vaccines. Some batches of Salk’s polio vaccine contained live virus which led to tons of people being infected upon vaccination and 5 children died.
what happens in post polio syndrome?
motor neurons compensate for the motor neurons that were killed when the body was infected with polio
what eventually happens to the motor neurons that don’t die upon infection?
they die later because they’ve spent their lifetimes compensating for the missing neighboring motor neurons that died
who is most susceptible to polio infection?
children under 5
