Influenza Flashcards
What are the complications associated with influenza?
Secondary staphylococcal pneumonia, viral pneumonia, Reye’s syndrome, Otitis Media, depression, and Myeloencephalitis.
What is Reye’s syndrome?
It is a cerebral oedema and fatty liver degeneration, most commonly found in children aged 6-12. It is caused by the height levels of aspirin used during influenza treatment.
Which mutated gene is linked to increased likelihood of serious illness and mortality from influenza?
IFITM3, people with this mutation must be vaccinated!
Describe the structure of the influenza virus…
It is spherical with a diameter of 80-120nm, though it is also pleiotropic so has be recorded in filamentous form. It’s genome is fragmented, single stranded, negative sense RNA which is associated with nucleoprotein.
What difference gives rise to influenza A, B and C?
The antigenic form of the nucleoproteins.
What is the role of haemagglutinin?
It is a virus binding protein subject to important variation.
What’s are the roles of neurominidase?
Removes sialic acid from residues so HA can bind; protects host cell from other viruses so there is no competition for replication; promotes virus release and infections by breaking down virus rafts.
What is the role of the M2 protein?
It is an ion enhange channel which allows protons to enter the virus, facilitating RNA release from its binding protein - a key step in replication.
How long does it take to make a vaccine and what are the consequences of this?
It takes six months and this means there may be a mismatch between the current circulation virus and the vaccine virus.
What is antigenic shift?
When a new strain of the virus appears, every 10-30 years, and the HA of this new virus does not cross react with the HA of the previous virus.
What is antigenic drift?
When there is a new, mutated virus which has some crossover to the previous virus.
What are the symptoms of influenza?
Sudden fever, respiratory problems, fleeting muscle pain, photophobia, and prostration.
