+RNA naked virus (polio, coxsackie, echo, rhino) Flashcards
what is characteristic of the picornaviridae family of viruses?
they are all naked, icosahedral capsid and ss+RNA
what viruses compose the picornaviridae family of viruses?
1) rhinovirus
2) poliovirus
3) coxsackie A and B
4) Echovirus
5) Hepatitis A virus
what is very important about rhinovirus?
it is the most common cause of the common cold
is there a vaccine for rhinovirus? why?
no, because there are 100 serotypes and they mutate very often (antigenic drift)
what is the biology of rhinovirus?
naked ss+RNA
how does rhinovirus trasmit?
aerosol
hand to nose transmission
what cells does rhinovirus target in primary infection?
targets respiratory epithelial cells
what cells and substances are important in order to get rid of rhinovirus?
interferon, CTL, and IgA
what is the treatment for rhinovirus?
no treatment
how infectious is rhinovirus?
highly infectious
when a cell is infected with rhinovirus, the cells will release what? these are responsible for what?
histamine and bradykinin, responsable for runny nose
what is the clinical presentation of rhinovirus?
sneezing,
rhinorrhea (runny nose)
clear mucus secretion
nasal obstruction
mild sore throat
couch
headache
what are the 4 characteristics of enteroviruses?
1) are naked ss+RNA
2) acid stable
3) usually more common from summer to autumn
4) transmitted through fecal oral route or respiratory droplets
5) controlled by washing hands
what are the enteroviruses?
1) poliovirus
2) echovirus
3) coxsackie
4) enterovirus
what cells does enteroviruses primarily target?
respiratory and GI epithelial cells
what is the enterovirus course of infection?
1) virion inhaled or ingested
2) virus targets resp or GI epithelial cells
3) viremia (causes flu like symptoms)
4) virus crosses blood-brain barrier causing neuro. sympt.
what is asceptic meningitis?
swelling of the meninges not caused by bacteria
how do you know asceptic meningitis is not caused by bacteria?
spinal tap reveals clear CSF
how is asceptic meningitis treated?
no treatment, self-resolving
what is the biology of the poliovirus?
naked ss+RNA
how is poliovirus transmitted?
fecal-oral route
fecal contaminated water (common source)
how is polio prevented?
polio vaccine
most poliovirus infection are what?
asymptomatic
what are the 3 clinical presentations of poliovirus?
1) asymptomatic
2) abortive poliomyelitis - is a nonspecific febrile disease
3) nonparalytic poliomyelitis, paralitic poliomyelitis, asceptic meningitis - the virus goes to the CNS
what is the clinical presentation of paralytic poliovirus?
1st phase: flu-like symptoms
2nd phase: cytolytic infection of anterior horn of spinal cord and motor cortex of brain
how does paralytic poliovirus look?
- asymmetric flaccid paralysis without sensory loss
- can be one limb or all four
what does bulbar polio cause?
can involve muscles of pharynx, vocal cords, and respiration
most poliovirus patients that die, are due to which polio?
bulbar polio
what is post-polio syndrome?
deterioration of originally infected muscles
how is the atrophy that occurs in polio?
it is asymmetrical
how is poliovirus prevented?
using salk vaccine and sabin vaccine
what type of vaccine is the salk vaccine? how is it taken?
killed, inactivated polio virus
taken as a shot
what type of vaccine is the sabin vaccine? how is it taken?
live attenuated
taken orally
what does the salk and sabin vaccine do?
causes a stornger or more efficient IgA response
what does Coxsakie type A cause? how does the symptom look?
acute hemorrhagic conjunctivits
pain, edema, photophobia, foreign body sensation
what is another name for coxsackie type A?
hand-foot-mouth disease
what virus causes this?
coxsackie type A
what is the clinical presentation of coxsackie type A?
First: lesion in mouth and tongue
1-2 days later: lesions appear in hands and feet
what is very important about coxsakie type B?
most common cause of viral myocarditis and pericarditis in newborns
what 3 things can coxsackie type B cause?
1) pleurodynia: pleuritic chest pain
2) myocarditis and pleurocarditis: unexplained and sudden heart failure
3) pancreatitis
what is the clinical presentation of coxsackie type B?
fever
chest pain
arrhythmia (myocardial cell necrosis)
heart failure
in coxsackie type B, when there is myocarditis, biopsy will reveal what?
lymphocytic infiltrate
what causes this? what is this?
coxsackie type B, leukocyte infiltration of myocardium
what is very important about echovirus?
it is the most common cause of asceptic meningitis
how can echovirus spread?
transplacentally
how can coxsackie type B be transmitted?
transplacentally
how is echovirus treated?
no treatment, self-resolving
what is the clinical presentation for echovirus?
fever
headache
vomiting
stiff neck
how do you confirm a diagnosis of any enterovirus?
CSF clear with leukocytes and slightly raised protein
