Lecture 18 - Influenza SARS-CoV-2 Flashcards
What is the name of the family of Influenza viruses?
Orthomyxoviridae
What are some viruses part of the Herpesviridae family?
Herpes
EBV
Varicella zoster
What type of genetic material does Orthomyxoviridae have?
ssRNA
-ve sense
What type of genetic material does the Coronarviridae specifically SARS-CoV-2 have?
ssRNA
+ve sense
What area of the body does influenza/flu affect?
Acute viral infection of respiratory tract
How infectious is influenza (relatively)?
Can people with mild or no symptoms transmit influenza?
Highly infectious
Even with mild or no symptoms, people with influenza can infect others
What are the shapes of orthomyxoviruses?
Spherical
Segmented negative single stranded RNA
What is the important viral enzyme that is important in the replication of the orthomyxoviruses which leads to them having high mutation rates?
Viral RNA polymerase
Why does presence of viral RNA polymerase lead to high levels of mutations in Orthomyxoviridae?
Viral RNA polymerase = high error rate
High error rate because RNA polymerase has no proof reading like DNA polymerase which leads to mutations
What are the 2 main surface antigens for Orthomyxoviridae?
Haemagglutinin (H)
Neuraminidase (N)
What is the function of the H surface antigen (Haemagglutinin) on Orthomyxoviridae?
Binds to the surface receptor on host cells starting the process for the virus to enter the host cell
What is the function of neuraminidase surface antigen (N) on the orthomyxoviruses?
Allows the virus to move away from the cell
What are the 3 types of influenza viruses seen in humans?
Influenza A
Influenza B
Influenza C
What is the order of severity of the 3 Influenza viruses seen in humans?
From most severe to least severe:
Influenza A (most severe)
Influenza B
Influenza C (least severe)
Which of the 3 strains of influenza has the most potential host organisms and what are a few examples?
Influenza A
Humans
Swine
Equine
Birds
Marine
Mammals
Which strain of influenza has only human hosts?
Influenza B
Which of the influenzas has both Antigenic shift + Antigenic drift?
Influenza A
What influenzas only have Antigenic drift (NOT antigenic shift)?
Influenza B
Influenza C
Which influenza is a mild disease WITHOUT seasonality?
Influenza C
Which influenza can cause large pandemics with significant mortality in young persons?
Influenza A
Which influenza can cause severe diseases which is generally confined to older adults or persons at high risk where pandemics are not normally seen?
Influenza B
What is the main animal reservoir for Influezna A viruses?
Birds (mainly wildfowl)
Which Influenza virus is the main cause of outbreaks, epidemics and pandemics?
Which Influenza virus causes less severe disease and smaller outbreaks?
Influenza A
Influenza B
Which group of people does Influenza B normally affect?
Children
Older adults
Immunocompromised