Paramyxoviruses

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Paramyxoviruses

• Fackrel_at_Uwindsor.ca
• paramyxo.ppt

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Paramyxoviruses

• Structure
• Classification
• Multiplication
• Clinical manifestations
• Epidemiology
• Diagnosis
• Control

Barons Web Site
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Paramyxoviridae

• Paramyxovirus - parainfluenza, mumps
• Pneumovirus - respiratory syncytial virus
• Morbillivirus - measles

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Rubella virus is a member of the Togaviridae!!!
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Structure Paramyxoviridae

• Enveloped 150-300 nm
• helical, pleomorphic symmetry
• SS RNA ,antisense monopartite

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(No Transcript)
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Viral Proteins

• RNA-directed RNA polymerase
• Hemagglutinin
• parainfluenza
• measles
• Neuraminidase
• parainfluenza

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Neuraminidase hemagglutinin activities are
different sites of the same protein
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Fusion protein causes syncytia formation
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Multiplication

• Antisense strand -gt sense RNA
• RNA directed RNA polymerase
• Viral proteins
• sense RNA template for antisense strands
• capsid assembly

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Paramxyovirus

• Parainfluenza virus
• Mumps virus
• Measles virus

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Parainfluenza Viruses
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ParafluClinical manifestions

• mild or severe infections
• lower and upper respiratory tract
• particularly in children

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Paraflu Classification

• types 1,2,3,4 in humans
• type 4 subtypes A B

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Paraflu Epidemiology

• occurs worldwide
• usually endemic
• primarily in young children
• reinfections common

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Paraflu Diagnosis

• clinical symptoms nonspecific
• Isolate virus
• Detect viral antigens
• Detect rise in specific antibodies

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No vaccine is available for Parainfluenza
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Mumps virus
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MumpsClinical manifestions

• systemic febrile infection
• children young adults
• swelling of salivary glands
• Parotid gland
• meningitis common
• encephalitis can occur
• orchitis oophoritis in adults

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Single mumps serotype

• shared antigens with paraflu type 1

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MumpsPathogenesis

• droplet infection
• viremia
• spreads to glands nervous tissue
• inflammation cell death

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MumpsEpidemiology

• worldwide
• endemic in urban areas
• intermittant in rural areas
• epidemic 2-7 years
• peak incidence Jan-May

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MumpsDiagnosis

• TYPICAL
• clinical diagnosis
• ATYPICAL
• isolate virus
• viral antigen in saliva of CSF
• Detect specific IgM
• Detect rising titer of IgG

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Mumps Defenses

• Interferon
• humoral immunity
• cell mediated immunity
• lifelong protection

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MumpsControl

• live attentuated vaccine
• long term protection
• reinfections can occur

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Morbillivirus

• Measles virus

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Measles Clinical manifestions

• coryza, conjunctivitis, fever rash
• maculopapular rash 1-3 days later
• Complications
• otitis, pneumonia, encephalitis
• SSPE (subacute sclerosing panencephalitis)-rare

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Measles Pathogenesis

• viremia
• multiples in cells of
• lymphatic system
• respiratory system
• skin
• brain

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MeaslesHost Defenses

• Interferon
• Humoral immunity
• Cell mediated immunity
• Life long protection

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Measles Epidemiology

• worldwide
• endemics epidemics
• mainly late winter-early spring

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Measles Incidence
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Measles Diagnosis

• Typical
• clinical manifestations
• Atypical
• Isolate virus
• Detect specific IgM
• Detect increase in IgG

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Measles Control

• Active vaccination
• Live attentuated virus vaccine
• long lasting protection
• Passive immunity
• measles hyperimmunoglobulin

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WHO MeaslesVaccination Strategy

• "catch-up" everyone aged 1-14 years
• "keep-up" 90 of children at age 12 months
• "follow-up" 3-5 years

WHO Report
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Pneumovirus

• Respiratory syncytial virus

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RSVClinical manifestions

• upper lower respiratory tract infection
• frequent in young children
• significant in elderly

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RSV Pathogenesis

• droplets
• direct contact
• infects ciliated epithelium of respiratory mucosa
• localized
• Antibody Dependent Cytotoxicity

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RSV Host Defenses

• interferon
• cell mediated immunity
• Humoral immunity
• Secretory immunity ( sIgA)
• reinfection possible

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RSV Epidemiology

• worldwide
• temperate climates
• epidemic winter and early spring
• infants young children

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RSV Diagnosis

• nonspecific clinical symptoms
• Isolate virus
• Detect viral antigen
• Detect IgM, IgA
• Detect icrease in IgG

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RSV Control

• no vaccine
• ribavrin as aerosol
• isolate patients in hospitals