RNA Viruse: Orthomyxoviruses And Paramyxoviruses Flashcards
Genome of Orthomyxoviridae
Spherical
-ssRNA genome : appears as 8 separate molecules
HA-hemagglutinin and NA-neuraminidase protein **
Classification of Orthomyxoviridae
Influenza A and B viruses
Influenza C virus
Tick-borne Orthomyxoviruses
Influenza A and B
Type A does not share ag with Influenza B
Many sub-types
Differ in HA or NA protein
14 subtypes of HA
9 subtypes of NA
Type specific antigens for Influenza A,B
Nucleoprotein
Matrix protein
Hemagglutinin
Sites for attachment to infect host cells (Salic acid)
H1-H15
Neuraminidase
Remove neuraminic acid from mucin and release from cell
N1-N9
Antigenic shifts of which protein results in pandemics
Haemagglutinin
Antigenic drifts in which proteins result in epidemics
Hemagglutinin
Neuraminidase
Forming new subtype
Antigenic shift
Forming new strain of virus
Antigenic drift
Large change in nucleotides of RNA
Antigenic shift
Small mutation of RNA
Antigenic drift
Occurs as a result of genome reassortment between difference subtypes
Antigenic shift
Occurs as a result of the accumulation of point mutations in the gene
Antigenic drift
An antigenic change can alter antigenic sites on the molecule such that a vision can escape recognition by the hots immune system
Antigenic drift
An antigenic change which results in severe alternation in HA or NA subtypes
Antigenic shift
Large and sudden mutation
Antigenic shift
Random and spontaneous mutation
Antigenic drift
Genome of Influenza C
Distinct genus
7 RNA segments
Single envelope glycoprotein in Influenza C function as HA
HEF—> fusion protein and esterase
Mutation capacity of HA,NA influence
The virulence
Replication of Orthomyxoviridae
In ciliated columnar epi of respiratory tract
In Orthomyxoviridae inflammatory response produced by CD4 T cells contributes to
Pneumonia
Clinical features of Orthomyxoviridae
Abrupt onset of fever, sore throat, nonproductive cough, myalgia, headache, malaise
Uncomplicated syndrome: 3-7 days
Wakness and cough: 2-3 weeks
Transmission of Orthomyxoviridae
Aerosols
Lab diagnosis of Orthomyxoviridae
Clinical diagnosis
PCR
Cell culture
EIA
Molecular methods
Immunofluorescence
Serology
Management of Orthomyxoviridae
Amantidine
Rimantidine
Ribavirin
NA inhibitors
Against which type of Influenza there are vaccines
A and B
Genome of Paramyxoviruses
Very fragile lipid envelope
Non-segmented linear genome
Spherical,helical symmetry but pleomorphic
Which virus has croup agent
Parainfluenza virus
Genome of Parainfluenza virus
SsRNA
Enveloped
Pleomorphic
5 stereotypes : 1,2,3,4a,4b
Classification of Paramyxovirus
Measles
Mumps
Respiratory Syncytial
Parainfluenza
Genome of Respiratory Syncytial virus
SsRNA enveloped
Respiratory syncytial virus causes
Lower respiratory tract illness in infants and young children
Mumps causes
Painful enlargement of the salivary glands — parotid glands
Which Paramyxovirus has vaccine
Mumps
Measles
Which virus causes Obliteration of the angle of the jaw
Mumps virus
Transmission of measles
Direct droplet contact
Koplik spots belongs to
Measles virus
