Lytic Viruses Flashcards
What is the size of the Picornavirus?
22-30 nm
What is the morphology of the picornavirus?
Icosahedral
nucleic acid of picornavirus
ssRNA, + polarity
Picornavirus: envelope or none?
none
Picornavirus: tegument or none?
none
What kinds of diseases are associated with Picornaviruses?
enteroviruses: paralysis (non polio and polio kind), common cold, meningitis, diarrhea, hand foot and mouth disease
Rhinoviruses: common cold
Hepatoviruses: hepatitis
Parechovirus: gastroenteritis, myocarditis, encephalitis
Kobuvirus: gastroenteritis
How are enteroviruses spread?
fecal oral, fomites, hands
What are the majority of polio infections like?
Inapparent infections (90-95%): virus found in throat or stool, but pt asymptomatic
The kinds of infections caused by polio
inapparent (subclinical)
mild illness
aseptic meningitis (nonparalytic polio)
paralytic poliomyelitis
Describe symptoms of paralytic poliomyelitis
asymmetric flaccid paralysis
lower extremities hit harder than upper
large muscle groups affected
how do you diagnose picornavirus
PCR
serology (neutralization, or 4 fold rise in titer to distinguish acute infection)
cell culture: time consuming
climate and time of year for epidemics of polio
temperate climate
summer
What are the three major epidemiological phases of polio?
endemic
epidemic late 1800s and early 1900s
post vaccine
What is notable about the proteins synthesized from Picornavirus mRNA?
first a single polyprotein that is cleaved to several products
How does Poliovirus enter cells?
canyons bind to receptor on cell