VIRO: FE ORTHO-CORONA Flashcards
What type of genome does Orthomyxoviridae have?
Single-stranded, negative-sense RNA.
It is the site of replication for Orthomyxoviridae.
Nucleus.
The process by which Orthomyxoviridae virions leave the host cell.
Budding from plasma membranes.
What environmental factors is Orthomyxoviridae sensitive to?
Heat, desiccation, lipid solvents, detergents, irradiation, oxidizing agents.
The meaning of ‘Orthomyxoviridae’ based on its etymology.
Correct mucus.
What disease does Orthomyxoviridae cause?
Influenza in humans and animals.
These are the surface glycoprotein projections found on Orthomyxoviridae.
Peplomers or ‘spikes’.
The two types of peplomers in Orthomyxoviridae.
Haemagglutinin (H) and Neuraminidase (N).
It is the function of Haemagglutinin (H) in Orthomyxoviridae.
Virus attachment and promoting entry of the virus.
What is the function of Neuraminidase (N) in Orthomyxoviridae?
Cleaving viral receptors and releasing virions from infected cells.
The primary target receptors for Orthomyxoviridae.
Sialic acid receptors on epithelial cells of the respiratory tract.
The structure of the Orthomyxoviridae genome.
6-8 segments of linear, negative-sense, single-stranded RNA.
Which genera of Orthomyxoviridae is the most significant pathogen?
Influenzavirus A.
What are the four genera of Orthomyxoviridae?
Influenzavirus A, Influenzavirus B, Influenzavirus C, Thogotovirus.
What mechanisms lead to new Orthomyxoviridae viruses?
Point mutation (antigenic drift) and genetic reassortment (antigenic shift).
It is the gradual process of small changes in HA and NA proteins.
Antigenic drift.
What is antigenic shift?
A major, abrupt change resulting in new HA and/or NA proteins, potentially causing pandemics.
What classification details are included in influenza virus isolates?
Type/host/geographical origin/strain number/year of isolation/subtype.
The difference between LPAI and HPAI in influenza viruses.
LPAI: Mild or no disease (H1-H16). HPAI: High mortality (H5, H7).
What is the natural reservoir for Influenza A viruses?
Aquatic birds, especially ducks.
How is Influenza A virus transmitted among birds?
Fecal-oral route.
Where does genetic reassortment of human and avian influenza viruses occur?
In pigs.
What are the common subtypes causing Avian Influenza outbreaks?
H5 and H7.
What role does viral hemagglutinin cleavage play in Avian Influenza?
It enables the production of infectious virions in respiratory and digestive epithelial cells.
What is the common cause of acute respiratory disease in horses?
Equine influenza.
It is the first known outbreak of Swine Influenza.
1918, USA.
What pandemic originated from swine influenza viruses in 2009?
H1N1 pandemic.
The viral family responsible for diseases like pneumonia, enteritis, and hepatitis.
Coronaviridae.
What are the known protein receptors for Coronaviridae?
ACE2, APN, DPP4.
It is a coronavirus affecting swine, causing transmissible gastroenteritis.
Transmissible gastroenteritis virus (TGEV).
Which coronavirus genus includes SARS and MERS?
Betacoronavirus.
What is the primary disease caused by Avian Infectious Bronchitis Virus?
Acute, highly contagious upper respiratory tract disease in chickens.
The disease caused by Turkey Coronavirus.
Coronaviral enteritis of turkeys (‘blue comb disease’).
What are the four genera of Orthomyxoviridae?
Influenzavirus A, Influenzavirus B, Influenzavirus C, Thogotovirus.
Which genus of Orthomyxoviridae affects both humans and animals significantly?
Influenzavirus A.
It is the mechanism by which new influenza virus strains emerge due to point mutations.
Antigenic drift.
What is the key characteristic of antigenic shift?
A major, abrupt change resulting in new HA and/or NA proteins, potentially causing pandemics.
How are influenza virus isolates classified?
Type/host/geographical origin/strain number/year of isolation/subtype.
What is an example of influenza virus classification?
A/equine/Prague/1/56 (H7N7).
What type of influenza virus is most commonly associated with pandemics?
Influenza A.
Which virus subtype is responsible for high pathogenic avian influenza (HPAI)?
Some H5 and H7 AI subtypes.
What is the role of pigs in influenza virus evolution?
Pigs act as mixing vessels for human and avian influenza viruses.
How is Avian Influenza transmitted?
Fecal-oral route among birds.
What diagnostic tests are used for Equine Influenza?
PCR assay, viral isolation, paired serologic testing.
What was the first known outbreak of Swine Influenza?
1918, USA.
Which viral family includes SARS and MERS coronaviruses?
Coronaviridae.
It is the genus of coronaviruses that includes SARS-CoV and MERS-CoV.
Betacoronavirus.
What coronavirus is responsible for feline infectious peritonitis?
Feline coronavirus (FIPV).
Which avian coronavirus causes a highly contagious respiratory disease in chickens?
Avian Infectious Bronchitis Virus (IBV).
It is the disease caused by Turkey Coronavirus (TCV).
Coronaviral enteritis (‘blue comb disease’).
What are the potential mechanical vectors of Turkey Coronavirus?
Darkling beetle larvae, domestic houseflies.
What is the morbidity rate of Avian Infectious Bronchitis?
1
