Orthomyxoviridae Flashcards
Influenza C
Contains human and swine firuses that rarely cause disease
Influenza A
Contain human, equine, swine and domestic poultry viruses
Clinical sign of what Orthomyxovirus
Avian Influenza
Transmission of orthomyxoviruses in poultry
By ingestion and inhalation
Isavirus
Contains only Infectious Salmon Anemia Virus
Thogotovirus
Contain tick borne viruses which infect livestock and humans in Africa, Europe and Asia
Equine Influenza virus replicates in
Epithelial cells of the upper and lower respiratory tracts
Avian Influenza vireamia leads to
Multifocal lymphoid and visceral organ necrosis
Swine influenza virus is transmitted through
Aerosols
Diagonsis of Swine Influenza Virus
Sudden onset of clinical symptoms
Virus identification - deep nasal swab
Diagnosis of Equine Influenza Virus
Clinical Presentation
RT-PCR
Swine Influenza virus replicates in
Upper respiratory tract
Genetic Shift
Changes in antigenic set up due to reassortment of gene segements
Avian Influenza viruses replicate in
Intestinal and Respiratory Tract
Transmission of orthomyxoviruses in mammals
Aerosol, droplet and fomite transmission
Diagnosis of Avian Influenza Virus
RT-PCR
Orthomyxovirus virion morphology
Pleomorphic
Segmented genome
Two types of glycoprotein spikes
T/F: Influenza virues are sensitive to heat, acidic pH and lipid solvents
True
Influenza B
Contain human viruses
Clinical signs of low pathogenic avian influenza
Cause upredictable losses do to decreased egg production
Transmission of orthomyxoviruses in aquatic birds
Virus is shed in feces - fecal oral transmission
Genetic Drift
Changes in antigenic setup due to point mutations - nucleotide substitution, deletion, insertions
Clinical signs of High pathogenic avian influenza
Cause sudden death without symptoms
Cessation of egg production, lacrimation, diarrhea, edema, cyanosis, torticollis
Why are pigs considered “mixing vessels” for influenza viruses
Because of their ability to become co-infected with both avain and human strains of influneza virus
Transmission of Thogotoviruses is by
Ticks - replication in both tick and mammal
Classification of Orthomyxoviruses is based on
The type of hemagglutinin and Neuraminidase
________________________
16 possible hemagglutinin
9 possible neuraminidase
Symptoms of Swine Influenza Virus
Appears in many animals at the same time
Fever
Nasal Discharge
May develop pneumonia and die
Most important viral respiratory disease of horses
Equine Influenza Virus
Avain Influenza Viruses are characterized as
Highly Pathogenic
Low Pathogenic
Clinical signs of Equine Influenza Virus
Rapidly spreads
Fever
Reddening of nasal mucosa
Conjunctivitis
Serous nasal discharge
Dry paroxysmal cough
Abortion
Transmission of Isavirus
Transmitted in water
