Paramyxoviridae 1 Flashcards
Paramyxoviridae categories:
Paramyxovirus (Parainfluenza + Mumps), Morbillivirus (Measles), Pneumovirus (RSV)
Paramyxovirus genome classification
ss (-)RNA Helical
Paramyxovirus Enveloped or not?
Enveloped
Paramyxovirus capsid shape
helical
Paramyxoviridae replicate in….
cytoplasm
Paramyxoviridae cellular effects… and how?
Multinucleated giant cells….via F protein
Paramyxoviridae systemic effects
Cell Mediated Immunity (causes many Sx but is needed to control infection)
Measles family name
Morbillivirus
Viremia is caused by which paramyxoviridae?
Measles and Mumps cause viremia.
Which Paramyxoviridae do not cause viremia?
RSV and Parainfluenza
Paramyxovirus genome is associated with what proteins?
N protein
Paramyxovirus polymerase complex is formed by what?
L and P proteins
M protein (Paramyxovirus) does what?
Associates with envelope, organizes and maintains virion structure
The envelope of paramyxovirus contains _____
viral attachment glycoproteins (HN/F —- H/F — G/F)
Paramyxovirus sub family includes
Paramyxovirus, Rubulavirus, Morbillivirus
Pneumovirus subfamily
Pneumovirus, Metapneumovirus
Members of Paramyxovirus (sub)
HPIV 1, 2, 3, 4
Replication of HPIV occurs in the
Cytoplasm
Virion surface of HPIV contains ___ and ____ glycoproteins
fusion trimer & attachment tetramer
Paramyx – Pneumovirus (genus) is what virus?
RSV
RSV is most common cause of
Fatal acute RTI in infants and young children
Re-infections of RSV possible?
Yes, throughout life
RSV hosts:
Humans only
RSV genome
ss -RNA
RSV capsid
Helical
Glycoproteins present in RSV?
F and G
RSV G protein doesn’t have…
HA/NA activity
RSV is an important cause of viral _____ and primary ______ in young children.
LRTI —– Primary bronchiolitis
RSV incidence peaks at
2-8 months
RSV bronchiolitis is usually _______
self limiting
In kids older than three, RSV infection is…
limited to URT
RSV atients who have chronic immunosuppression are at risk for…
Pneumonia (LRT disease)
RSV incubation period
3-6 days
RSV replicates in _____ and spreads to ______
URT, LRT
RSV bronchiolitis is a result of..
host immune response
How long is newborn protected from RSV by mom’s antibody?
NO PROTECTION by maternal antibody
RSV bronchiolitis is virus-induced….
necrosis of epithelium
RSV spreads from cell to cell in the URT, causes ____ formation
Syncitium formation
Incidence of RSV infection in children
Most children have had by age 4
High risk groups for RSV infection
Kids in daycare, crowds, multiple birth sets…. Premature babies, CHF, SCID disease patients are at risk for SERIOUS disease.
RSV strongly suspected in…
infants with LRT disease
RSV diagnostic tests
IF staining Antibody, ELISA, PCR….. ISOLATION of virus to see CYTOPATHIC effects
RSV antivirals
RIBAVIRIN (nebulizer) ……… PALIVIZUMAB (passive immunization, monthly IM inject)
Human parainfluenza virus is in what family?
paramyxovuris
PIV subgroups
1-4
PIV genome
ss -RNA
PIV genome segments?
Unsegmented
PIV enveloped or not?
Enveloped
PIV glycoproteins
Hemagglutinin-Neuraminidase [HN] for virus attachment, Fusion [F] protein (spikes), and Matrix [M] protein.
PIV capsid shape
helical
PIV causes ___ and ____ infections (anatomically)
URT and LRT
HPIV are also a cause of ______ infections (epid.)
community-acquired RTI’s
Are HPIV reinfecitons possible?
yes, but they tend to be less severe, and involve the URT
HPIV causes this named condition?
Croup
Croup is usually caused by what virus subtypes?
HPIV 1, 2, 3
Major symptom of croup
inspiratory stridor
Which HPIV subgroups cause bronchiolitis
1-4 (all of them)……. 1 +3 are the most common
Which HPIV subgroups cause PNA? What share of total cases are caused by these?
1 + 3 are most common. (10% of outpatient cases)…….
HPIV associated with ____ in elderly
secondary bacterial PNA
25% of ____ are due to HPIV (subgroups?)
tracheobronchitis (mostly 3)
_____ seems to be the most common HPIV that causes other infections
HPIV 3
HPIV2 causes _______ in immunocompromised patients
Giant Cell PNA
HPIV viremia is _____
its is RARE
After cell entry, HPIV damages ____ cells
ciliated
Incubation period for HPIV
1-7 days (one week)
Systemically, HPIV causes ____ to be made
Cytokines (IL-2, 6) (IFN-a, TNFa)
What is the pathophysiology behind croup?
IgE specific to HPIV causes HISTAMINE release in trachea, causing edema
HPIV continues to be excreted ____ days (from respiratory tract)
3-16 days
HPIV transmission routes
Direct contact, surfaces, and inhalation
HPIV can remain aerosolized for ____
over an hour
In children older than 5, what percentage have antibodies to HPIV?
90-100% for HPIV-3, 75% for HPIV-1+2
Which strains are biennial, which are annual
HPIV 1 biennial, HPIV2 is annual or biennial FALL outbreak, HPIV 3 is spring or early summer peak