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82 Cards in this Set
- Front
- Back
Paramyxoviridae
naked or enveloped? |
enveloped
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Paramyxoviridae
describe nucleocapsid |
enveloped, helical
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Paramyxoviridae
shape? |
pleomorphic (156-300 nm in diameter)
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Paramyxoviridae
What are the two viral glycoproteins in the envelop? |
a. Fusion protein -F protein (penetration)
b. Viral attachment protein (VAP) HN, H or G depending on virus |
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What are the three genera of Paramyxoviridae family?
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Morbillivirus
Paramyxovirus Pneumoviruses |
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Name an example of Morbillivirus.
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measles (rubeola)
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Name three Paramyxioviruses/
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Paramyxovirus, mumps virus, parainfluenza 1-4
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Name two Pneumoviruses.
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Respiratory syncytial virus (RSV), Metapneumovirus
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Paramyxoviruses are respiratory viruses transmitted by ____.
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aerosols (virus in respiratory droplet)
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Paramyxoviruses
Where does initial replication occur? |
respiratory tract
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Paramyxovirus infections cause cell to cell fusions resulting in ____ ____.
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syncytia formation (aka, giant cells or polykarions)
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Most paramyxoviruses can spread from cell to cell, evading ____ ____.
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neutralizing antibody
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Paramyxovirus VAP causes ____.
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haemagglutination
(**not true for RSV) |
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Paramyxovirus
Indirect pathology is caused by ____ ____ ____, which is also needed to clear the virus. |
cell mediated immunity
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How many measles (rubeola) serotypes?
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only one!
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Infection with measles (rubeola) causes what?
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red measles (rash disease)
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How long does immunity to measles (rubeola) last?
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lifelong
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What creatures can host measles (rubeola)?
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only humans
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Measles Virus clinical symptoms.
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CCC&P
Cough, Conjunctivitis, Coryza & Photophobia (**Coryza is acute rhinitis) |
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After one week of infection, what are symptoms of Measles Virus?
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Macuolopapular rash & high fever
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What are Koplik's spots and what are they diagnostic for?
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small white spots (1-2 mm) resembling salt grains, found on buccal mucosa & other membranes
usually appear 1-2 days before macuolopapular rash **Measles Virus! |
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Is maculopapular rash (red measles) contagious?
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NO!!
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Describe maculopapular rash.
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-mix of macules and papules
-extensive rash, beginning below ears, then spreading -takes 1-2 days to spread over body -fades 1-2 days after it appears |
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Measles infections begin in the ____ ____, but this virus causes systemic disease.
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respiratory tract
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How is measles virus spread through the body?
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viremia
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What causes the characteristic measles rash?
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T-cells reacting with virus infected cells in the capillaries of skin.
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What are some complications of measles virus?
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Pneumonia and bacterial complications are responsible for the majority of measles death (60%)
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Encephalitis occurs in 0.5% of measles cases (15% fatal), and ocurs 7-10 days after infection.
What causes this complication? |
demyelination of neurons - primary damage caused by virus
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If you are going to get measles, do you want atypical measles?
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NO! --> way more intense.
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What's the problem with atypical measles?
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Immunopathology associated with a wild type measles infection of a patient vaccinated with inactivated virus vaccine --> insuficient protection induced by vaccine, but enhanced immunopathology.
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What is SSPE?
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Subacute sclerosing panencephalitis.
2-20 years after measles infection, infecting virus is defective. |
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Measles Virus - Laboratory DIagnosis
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Based on clinical presentation (rash, kopolik's spots, CCC&P)
MAB and other diagnostic reagents available. |
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Measles prevention
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live, attenuated measles vaccine
(included in MMR, provides lifelong immunity) |
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Why shouldn't killed vaccine be used for measles vaccination?
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predisposes recipients to atypical measles
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Measles - Antivirals?
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nope
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Measles - Passive Immunity
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effective and available to immunocompromised pts
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Mumps - genus
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paramyxovirus
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Mumps - symptoms
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acute, benign viral parotitis (and swelling of other glands)
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Mumps - typically fatal?
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nope
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How many serotypes of mumps virus?
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one
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How is mumps virus spread to parotid and other glands?
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viremia
stensens duct (for parotid) |
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How is mumps virus acquired?
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aerosol droplet, fomites
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Mumps - initial replication
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URT
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Mumps causes damage via ____ pathology.
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indirect
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With mumps virus, what percent of pts have CNS infection?
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50%
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Pre-vaccination, what percent of the population would be infected with mumps virus?
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90% -- highly infectious!!!
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Mumps - How long do pts shed virus before symptoms?
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7 days
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Are all pts infected with mumps virus symptomatic?
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nope - some are just carriers (lucky ducks)
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Mumps - When is incidence higher?
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winter & spring
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Mumps virus - Laboratory Diagnosis
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virus isolated from saliva, URINE, pharynx, CSF
serology used to detect antiviral antibody Hemagglutination |
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Mumps Infection - serology findings
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4x increase in anti-mumps IgG
appearance of anti-mumps IgM |
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Mumps - Treatment
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treat symptoms (discomfort) - not fatal, no antivirals, just your normal everyday drag.
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Mumps - Vaccine
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live attenuated virus
part of MMR vaccine |
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Parainfluenza - genus
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paramyxovirus
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Parainfluenza - serotypes
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four serotypes
1, 2 + 3 - important agents of lower respiratory tract infection in younger children (associated w/ croup) ***serious disease in children!! 4 - mild UTR symptoms |
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Parainfluenza - spread
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spread by aerosol route or direct contact
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Parainfluenza - viremia?
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nope - no systemic spread
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Which cells does parainfluenza infect?
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epithelial cells in URT
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Parainfluenza - direct pathology
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cause GIANT CELL formation
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Parainfluenza - general symptoms
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cold like symptoms
**croup is more serious (sub-glottal swelling, cough, tachypnea, tacycardia, suprasternal retraction) |
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Parainfluenza - croup symptoms
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cold like symptoms
**croup is serious in children! sub-glottal swelling, cough, tachypnea, tacycardia, suprasternal retraction |
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How long does it take pts to recover from parainfluenza infection generally?
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48 hrs
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Is reinfection common with parainfluenza?
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yes - severity of disease declines with reinfection
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When is parainfluenza most common?
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1+2 in fall, 3 year-round
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Parainfluenza - Lab Diagnosis
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readily isolated from nasal and respiratory secretion
identified by CPE, hemagglutination, Hexaplex PCR |
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Hexaplex PCR assay
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parainfluenza viruses 1, 2, 3, RSV types A and B, influenza types A and B
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Parainfluenza - treatment
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**infants w/ croup need careful monitoring!!
treat symptoms with nebulizers |
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Parainfluenza - antivirals?
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no
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Parainfluenza - vaccine?
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nope - no effective killed vaccine has been established that will stimulate local immunity. no attenuated vaccine either.
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Respiratory Syncytial Virus (RVS) - genus
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paramyxovirus
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How does RSV differ from other paramyxoviridae?
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lack of neuraminidase activity
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Does RSV hemmagglutinate red blood cells?
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nope
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RSV - how does infection occur?
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aerosol-borne virus (like all the other paramyxoviruses)
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RVS infects the ____ respiratory tract.
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lower
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RSV - direct pathology??
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YES - direct cytopathology caused by viral fusing of infected and uninfected cells (F protein)
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RSV symptoms
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from cold-like to pneumonia, pts may exhibit fever, tachypnea, tachycardia and wheezing
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How infectious is RSV?
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"blows through daycares"
very common, very contagious, widespread. |
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When do RSV infections primarily occur?
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winter
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RSV - Laboratory Diagnosis
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virus detected using kits that test for viral antigen - Hexaplex PCR
Nasal or respiratory aspirates tested by IF or ELISA (fast) Virus isolation (difficult) Serology (never used) |
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RSV - antiviral?
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Ribavarin - administered by nebulizer (usu in clinic or hospital setting)
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Describe Ribovarin efficacy.
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guanosine monophosphate analogue -- inhibits nucleoside biosynth, mRNA capping, RNA replication
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RSV - passive immunization?
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yes - available for immunocompromised pts or premature babies
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