Influenza is a highly contagious respiratory illness caused by the influenza virus. The virus can potentially cause mild to severe illness, and can lead to significant complications in those with comorbid conditions like asthma and COPD, and in those with compromised immune systems. Significant problems, including death, can also arise in the elderly and young children. There are two types of the virus, Influenza A and B. Type A is usually more severe.
Flu season begins to increase in October and typically peaks in December through February, although flu season can last until as late as May.
Influenza spreads from person to person by droplets in the air secondary to coughing, sneezing and talking. Virilus can get into nose, mouth and lungs. Not commonly spread through tactile means, although hand washing is an important step in preventing the virus from spreading.
People are most contagious during the first 4 days after being infected, but symptoms typically begin within first 48 hours of exposure. Infected persons can spread the virus prior to symptoms and usually up to 1 week after getting ill.
Symptoms of onset include sudden onset of fever, chills, malaise, cough, sore throat, runny or stuffy nose, headaches, moderate to severe muscle and/or body aches, vomiting and diarrhea (seen more in pediatric population). Influenza differs from the common cold whose symptoms are usually milder.