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45 Cards in this Set
- Front
- Back
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Polio structure
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+ssRNA Picorna virus
non-enveloped and acid stable |
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who are the hosts for polio
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humans are the sole host
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method of infection for polio
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fecal oral
contact with respiratory secretions hearty virus that can persist in the environment for long periods of time |
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incubation period
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3 days to a month
typically 1 to 2 weeks |
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who is most at risk for a symptomatic polio infection
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older children with more developed immune systems
<2 = asymptomatic disease |
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what is the symptom associated with the bulbar form of polio
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respiratory paralysis
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what CNS structure is rarely affected by the polio virus
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motor cortex of the brain
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how does a polio paralysis typically present
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asymmetrically
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what protein is needed to initiate polio RNA replication
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VPg protein
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if a polio RNA has the VPg protein attached to it (during a lytic cycle) will it continue to produce more RNA copies of the virus (via RNA polymerase)
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No, the VPg tagged RNA is directly encapsulated and ready to go
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what % of polio infections are actually clinically evident?
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~ 1%
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what are the clinical features of an abortive polio illness
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fever/ headache
N/V malaise 4-8% recover spontaneously |
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what are the clinical features of a non-paralytic polio illness
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fever/headache
N/V malaise stiff neck and back 1-2% recover spontaneously |
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clinical manifestations of paralytic poliomyelitis
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~ 1% of infections
minor disease that progresses to major disease in 1 to 3 days N/V, fever/headache, muscle stiffness, paralysis paralysis maximal a few days after onset |
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what neurons are typically damaged in paralytic poliomyelitis
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lower motor neurons
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clinical manifestations of bulbar paralysis
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CN damage
difficulties with: speach, swallowing, eye movements, facial functions involvement of the bulbar/medullary resp center or the diaphragm lead to resp fail |
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is there only one polio virus
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no, there are 3 serotypes with little to no crossreactivity
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can the Inactivated polio vaccine induce an infection in a human
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no, the inactivated vaccine is not associated with disease
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is the IPV as effective as the OPV
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no, it is not as immunoprotective
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what is the difference btw the IPV and the e-IPV
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the e-IPV has a higher inoculate of all three virus strains to ensure a larger response
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what are 2 other names for the Sabin vacci9ne
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live polio vaccine
oral polio vaccine (OPV) |
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how many cases of VAPP were seen each year in the US
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~10
it is a back mutation to the paralytic strain CDC now recommends against it in favor of the IPV |
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what happened in 2006 during vaccine administrations in nigeria?
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a VAPP epidemic occurred
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though SV 40 can cause malignancies in the lab, can it do so in humans
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No, unless you are a fetus of a mother injected with IPV
there has been a link established for greater incidences of brain tumors in this case |
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what is progressive multifocal leukoencephalopathy (PML)
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demyelination of oligodendricytes due to the JC virus
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what is a suspect for the development of PML in an immune-competent, non-elderly person
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SV40 mediated
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what happened to 4 Amish children in Minnesota in 2005
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the were infected with a Polio virus, vaccine strain
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how were the ECHO and Coxsackie viruses discovered?
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accidentally, while examining feces during a polio epidemic
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Do ECHO and Coxsackie viruses typically cause disease?
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No, but they do occasionally result in CNS infections
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what are the clinical manefestations of ECHO/Coxsackie viruses in a newborn
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fever, vomiting, anorexia, rash, URT infection, bulging anterior fontanelle
ECHO death= hepatic failure Coxsackie death= myocarditis |
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what are the clinical manefestations of ECHO/Coxsackie viruses in a newborn
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fever/headache
nuchal rigidity |
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which enterovirus can not be cultured
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Coxsackie A virus
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how should you diagnose an enterovirus
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with culture AND serology when possible
RT-PCR typically used |
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what are the sites of isolation for enteroviruses and their specificities
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fecal- most sensitive, least specific
Nasal- most specific CSF- only good for a highly invasive disease, late in the process |
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what is the treatment for enterovirus infections
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supportive only
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epidemiology of enteroviruses
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usually in the summer and fall
probability and severity decrease with age (polio is the exception) fecal oral each season typically shows only a few serotypes (Coxsackie B currently) |
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what is the link between infant/immunocompramised enterovirus disease severity and the bodies method for eliminating them
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the body uses Immunoglobulins to eliminate the disease, infants and immunosuppresed individuals do not have these
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diseases "possibly associated" with enteroviruses
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type I diabetes
inflammatory myositis chronic fatigue synd |
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what is the morphology of Lymphatic Choriomeningitis Virus (LCM)
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arenavirus
2, -ssRNA (one is ambisense) enveloped and 10x larger than typical enteroviruses |
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what are the hosts for arenaviruses
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its zoonotic
causes chronic infections of rodents (LCMV most prevalent) |
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what are the clinical manifestations for LCM
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typically Flu like (encephalitis rare)
meningitis uncommon, but can last from 1 week to months risk to fetuses |
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what is going on with petsmart, regarding LCMV
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guy got it from a transplant liver
the donor got it from a hamster purchased at petsmart |
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what might you suspect in cases of aseptic meningitis?
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LCMV if the person has exposure to rodents
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transmission of LCMV
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rodent excrement
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when do you typically see LCMV infections?
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in the autumn and winter months
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