What is Influenza?

Friday, 8 January 2021

Influenza is a respiratory tract infection caused by influenza viruses.

What is the Influenza Virus?

RNA virus, Orthomyxoviridae group
Easy to mutate
Has various types: A, B, and C

Symptoms caused by type A are heavier than type B, while type C is more likely to cause no symptoms.

Type A is also the easiest to mutate (both minor mutations and major mutations)

What are the symptoms of influenza-induced disease?

Fever
Cough
Cold
Headache
Throat pain
Sore
Weak

Why should influenza be watched out?

INFLUENZA is very EASY TO DELIVER (Friends, Family Members, and Patients)

Transmitted by air through mediation

Cough
Sneezing
Saliva
Objects contaminated by coughing, sneezing and saliva

INFLUENZA reduces PRODUCTIVITY

Not going to work or not going to college because of influenza

An ounce of prevention is worth a pound of cure

Higher medical costs
Discomfort due to symptoms of influenza for several days (dizziness, headache, rheumatic pain, etc.)

GROWING OTHER CHRONIC DISEASES

Strengthening heart disease
Strengthening lung disease
Prevent diabetics who are susceptible to flu
Can result in death from pneumonia

EASY and FAST to MUTATE

Influenza viruses are viruses that are very easy to change (mutate) compared to other viruses. Mutations that occur can be small / minor (antigenic DRIFT) and large / major (antigenic SHIFT).

Antigenic DRIFT

Minor changes in the HA (haemagglutinin) and NA (Neurominidase) influenza viruses
Occurs in all types of influenza viruses

Seasonal Influenza Causes

Antigenic SHIFT

Changes occur in RNA
2 different strains of the virus merge to form an RNA segment change - called "reassortment", occurring in one 'reservoir' - infected host
Causes major changes to HA & NA
Only occurs in type A viruses
Causes of influenza pandemic
Causes pain and more death

What are HA & NA?

HA and NA are the buttons on the surface of the influenza virus

HA (Haemaglutinin Antigen)
Playing a role in attachment of the virus to respiratory epithelial cells (host) so that it can enter into the host cell.
NA (Neuraminidase Antigen)
Playing a role in releasing viruses which have multiplied in host cells so that they can spread to other cells.