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55 Cards in this Set
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what is encephalitis |
sx indicating extensive brain involvemnet- seizure, visual change, paralysis
combination of findings |
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what was the history of poliomylitis
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infantile paralysis was rare until 20th century
**b4 water was dirty adn ppl got polio as infants and it was NBG, now with clean water ppl got it later in life and it was a worse outcome |
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what is the problem that comes with the enterovirus polioviurs
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poliomyelitis- destruction of motor neurons in spinal cord. feared but RARE
*flaccid paralysis **disease of "civilization" - clean the water onset of disease is delayed and sx are worse |
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whats the dx for poliomylitis
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fever
asymmetric flaccid paralysis serology isolate virus in the poo PREVENTION is key **civilization disease |
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whats the structure of poliovirus
whats it like in acid |
picorna virus, ssrRNA, NO envelope- no lipids
Acid STABLE similar to rhivivirus- picovir (pleconaril) can be used 3 AG types that cross react |
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wht feature of polio has allowed us to nearly erradicate it
how is it transmitted |
it ONLY affects humals (sole natural host)
wont live in environment for a long time (?? thought it lived in milk water and food) vaccination is life long protection **3 AG types, need immunization against all 3 types **fecal oral spread or respiratory |
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what is the seasonality of poliovirus
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summer sutum in temperate zone (swimming pool use)
no peak in tropical regions **recall this is the one that is structurally (ssRNA, small) similar to rhinivirus and picovir is used |
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why is polioviris persistent
what is the incubation period what is the infectious period |
tough! lasts a long time in milk, food, water
1-2 week incubation most infectious at first week of illness |
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what is the pathogenesis of poliovirus
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enters GI via M cells, multiplies in pharynx and sm intestine, viremia spread to draining LN
seeds to CNS- infection of ant horn of brain stem--> respiratory paralysis (bulbar form) and motor cortex (rare) |
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where in the CNS does poliovirus do
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1. Bulbar Form: ant horn of spinal cord, brain stem- respiratory paralysis
2. Motor cortex- rare (paralysis, via dead nerve not destruction of sk mm tissue) |
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T or F
paralysis in polio is due to infection and subsequent death of mm fibers |
FALSE! its death of neural cells
**virus enters from blood or retrograde axonal flow **paralysis is asymmetric flaccid **2-3 days, maximal paralysis with rebound up to 6 weeks |
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what does the bulbar form of polio affect
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involuntary respiratory mm
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what is "infantile paralysis" of polio
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misnomer! infants who get polio do really well! its the older kids who were just using their mm heavily (ie swimming) that get the worse paralysis
**paralysis is maximal 2-3 days, then you recover until 6 weeks. at 6 weeks revocery is maximal |
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what is the genome of poliovirus
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ssRNA
+ sense (no reverse transcription needed, serves as mRNA directly) IRES- internal ribosome entry site. mimics mRNA and will cleave ALL other mRNA's so they are not recognized |
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what is IRES
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its the internal ribosome entry site in poliovirus
**it acts as mRNA and blocks ALL other mRNA from being translated into protein |
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tell me about polio polypeptide processing
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processed by viral protease to make caspid units
RNA dependent RNA polymerase and additional viral RNA replication accessory proteins that will make new +sense RNA genome **new RNA is linked to the viral protein VPg- this is needed to initiate viral RNA replication |
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what are the clinical syndromes of poliovirus
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1. MOST- not clinically evident
2. Abortive illness- general fever, maliage, HA, nausea/vomit. most recover spontaneously 3. Non paralytic poliomylitis: fever, HA, maliase, N/V, STIFF NECK/BACK. 2-10 day with spontaneously recovery 4. PARALYTIC POLIOMYLITIS- rare but feared. asymmetric flaccid paralysis (LMN damage) damages nerves. get max paralysis 2-3 days and max recovery at 6 weeks 5. post polio syndrome: mm atrophy years after infection bc of overuse of compensating nerves |
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ok so when we think polio we all think paralysis but that is not common at all, what is MUCH more liekly
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1. inapparent infection
2. abortive illness 3. non paralytic 4. post polio |
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whats bulbar paralysis, what is it associated with
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polio
**CN nerve involvemnet- speech, swallow, facial mm movement **repsiratory center- life threatening **now can live in iron lung to help breath |
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martha mason
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the gal with bulbar poliovirus that lived for a really long time in the iron lung
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whats post polio syndrome
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years and years after initial infection the mm being to atrophy (initial infection WAS Paralytic)
its NOT a latent infection, its atrophy after compensation of overused nerves **gradual clinical course |
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what is a long term complication of paralytic polio
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post polio syndrome
the compensating nerves get worne out from overuse syndrome **gradual clinical course |
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how can we prevent polio since that is such a good way to treat it!
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recall 3 AG variants (serologic types) exist and ALL must be vaccinated against!
3 vaccines 1. IPV (inactivated polio virus) not as effective as OPV, 4 shots over 1-2 years 2. eIPV- enhanced inactivated polio. ensures all 3 strains get good immune response 3. OPV- oral, live. can get back mutations that cause paralytic polio so NOT sued in US |
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what are the 3 polio vaccines
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1. inactivated- 4 shots over 1-2 years
2. e inactivated polio vaccine- ensures good immune response to all 3 strains 3. Oral- live! not used, can back mutated and cause paralytic disease |
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is travel and polio a concern
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you bet! there have bern 24 countries where polio was brought into previously polio free areas
CONTINUE VACCINATION 2005 in MN, 4 kids with PV vaccine strain even though vaccination hadnt been given in 5 years! |
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what do we need to consider when given OPV vaccine
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the LIVE oral vaccine- better to use in countries that have some immunity already
can get poliovirus VACCINE strains |
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whats the deal with polio vaccine and SV40
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SV40 was transmitted along with the polio vaccine
the polio virus vaccine was make in monkey and the monkey has the SV 40 virus SV 40 can cause cancer but IT NEVER HAPPENED IN THE PTS who got the SV40/polio vaccine **there were some problems with the babe if a preggo mom took them |
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ok so SV40 and polio vaccine is not really an issue, what might be
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PML- progressive multifocal leukoencephalopathy
opprotunistic demyelinating infection due to JC virus induced lysis of oligodendrites that form spreading leisions 88disease of old immunosuppressed |
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did OPV intorduce AIDS to humans
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nope
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whats the break down if picorna virus
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Enterivirus- infect via gut
Rhinovirus **entero typically associated with intestinal infection but there is lots of tissue tropism, so rhino is exclusive to airway |
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is CNS infection with enterovirus common in us
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yes, even through polio is controlled for the most part
**newborns and immunocomprimised are at greatest risk |
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describe the non oplio enterovirus. what are they
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ssRNA, small, + sense (same as polio),
still picornavirus but are very different from polio 1. ECHO 2. Coxsackie 3. Enterovirus 70 |
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tell em about ECHO virus
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non- polio enterovirus
**accidently discovered in poop, can have virus buthave no disease |
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tell me about coxsackie
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similiar structure to polio but different RNA
A- myotitis with acute inflammation/necrosis of coluntary mm fibers B- degeneration of BRAIN adn voluntary sk mm |
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how will a newborn present with ECHO or Coxsackie
what about an older kid or adult |
NEWBORN
sudden fever, vomit, anorexia, rash, meningeal inflammation, bulging ant fontanelle, Live failure in ECHO, Myocarditis in Cosackie OLDER: fever, HA, nuchal rigidity |
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ok so a newborn with the non polio enterovirus ECHO or Coxsackie will both have sudden fever, vomit, anorexia, rash, bulging ant fontanelle etc. how can you tell them apart
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ECHO- liver failure
Coxsackie- myocarditis **commonly cause meningitis, not severe unless in the newborn |
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encephalitis is most commonly caused by what 3 things
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1. HSV
2. arbovirus 3. enterovirus |
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how are coxsackie and ECHO dx
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*hard to culture, cox A wont grow in culture (throat or fecal)
*can have non sx shedding of virus, and 30% of + will show - **CSF samples take a long time to be + *serology might help or reverse transcriptase PCR |
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whats the dif btwn coxsackie A and B
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A- voluntary mm involvement
B- brain adn voluntary mm involvement |
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what does it mean when you can isolate coxsaxie or ECHO from...
Poo Nasopharynx CSF/Blood how do you treat |
Poo- most sensitive but least disease specific
Nasopharynx- better to link the disease CSF-Blood: not usually here so when you find it its an invasive disease Tx is supportive, no antivirals. Perhaps picovir bc its like a rhinovirus |
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are there antivirals for both polio enterovirus AND non polio
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just polio
IPV eIPV OPV |
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who gets non polio enterovirus like ECHO and Coxsackie
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young kids in the summer/fall
**young kids get REALLY sick, unlike polio where it was better to get it as an infant *fecal oral |
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what enterovirus is BAD for inants
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non polios
**summer/fall, fecal oral, |
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what other disease is like the flu in that each season there are just a few viral serotypes that predominate, what is the season
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non polio enterovirus
summer fall |
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how are enterovirus cleared from us, what implication does this have on infants who get it (non polio- coxsackie/echo)
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with AB, so the more AB your mom has hte better the infant does :)
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what is the best way to treat non polio enterovirus
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prevention!! NOT likely to get a vaccin
wash your hands you yucky kids!! its fecal oral bc they are similar to rhinovirus they are thinking of pleconaril (picovir) |
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what is Enterovirus 70
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non polio, acute hemmoragic conjunctivitis
super contagious, rapid onset of pain and swelling and bleeding |
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what are some controversial enterovirus associated diseases
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1. Juvenile onset DM- coxsaxkie B
2. Inflammatory myositis- rheumatological disease 3. Chronic Fatigue- XMRV, not the case! |
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what is lymphocytic choriomeningitis (LCM)
structure, genome, etc |
areanvirus
ambisense ssRNA enveloped (all others in this lecture were NON enveloped) HUGE, this virus has chromosomes and can replicate in cytoplasm causes preventable meningitis |
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who is infected with LCM
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rodents, human zoonoses
*infection rates are low |
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how do arenavirus replicate (ie LCM)
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ambisence (the polio and non polios- coxsaxkie, echo, entero 70 are + sence enveloped)
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what are hte clinical manifestations of LCM
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MENINGITIS is UNCOMMON!
encephalitis is RARE **flue like illness **risk to baby if mom is preggo **also a problem if a transplant is infected nad host is immunocomprimised |
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what happened with petsmart
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sued after a kid with a liver transplant got sick after playing with his LCM + hamster
**animal can be certified LCM free but then can pick up up from anything! NEVER have RODENTS! bc its really super dangerous to have flu like sx (meningitis nad encephalitis is RARE) ;) paranoia! |
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if you have aseptic meningitis what might be the culprit
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aseptic- no pathogen is isolated (recall CSF will get pathogen with cox and ECHO but it takes a week or longer)
LCM- with history of rodent exposure **PREVENT LCM with rodent control |
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who gets LCM
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any age group who plays with rodents in autumn- winter
**the others were more common in summer |