Influenza A viruses are further categorized onto subtypes based on two surface glycoprotein antigens: hemagglutinin (HA) and neuraminidase (NA).
The flu attacks the respiratory system and ranges from mild symptoms that mimic a severe cold to a deadly infection of the body’s major organs.
The major risk of influenza is that it can make an underlying disease worse. If the person have diabetes or asthma or a heart condition, being sick with influenza can exacerbate those illness.
Influenza also can predispose the person to other infections, such as bacterial pneumonia.
Influenza is typically transmitted from infected mammals though the air by coughs or sneezes, creating aerosols containing the virus and from infected birds through their droppings.
Influenza can also be transmitted by saliva, nasal secretion and feces. Symptoms most commonly associated with influenza include fever, muscle aches and pains, chills, lacks of energy, sneezing and runny nose, cough and severe headache.
What is influenza?
