Flu
• Definition
· Influenza is a seasonal viral illness affecting the respiratory track.
• Overview
· Influenza outbreaks occur every winter season.
· Influenza symptoms have a very abrupt onset and are more severe then a simple “cold”.
· Influenza infects up to 250,000 people in the United States every year
· Influenza infections typically resolve within 7 days.
• Types
· Influenza A and Influenza B are the 2 types of the Influenza virus responsible for most flu outbreaks.
· Influenza A virus type is identified by 2 types of proteins (H protein and N protein) found in the surface of the Influenza virus and there are 16 distinct H protein types and 9 distinct N protein types.
· Influenza A type changes almost every year and the extent of the infection is based on the changes in the surface proteins(H protein and N protein).
• Symptoms
· Influenza A infection appears similar to a simple “cold” but the onset is very fast and symptoms are more severe.
· Influenza A symptoms include the abrupt onset of
fever
chills
dry cough
muscle pain
joint pain
fatigue
sore throat
• Complications
· Influenza A infection complications more often occur in elderly patients or people with impaired immune systems.
· Influenza A infection can be complicated by the development of pneumonia and respiratory difficulties.
· Reye’s syndrome, which is a severe form of liver failure, which can occurs in young children who are given aspirin when infected with influenza or chicken pox
• Treatment
· Influenza A infections can typically be treated with prescription medications:
Tamiflu
Relenza
Amantadine
References
Advisory Committee on Immunization Practices. Prevention and Control of Influenza: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 2006 Jul 28;55(RR-10):1-42. [PMID: 16874296]
Prevention of antigenically drifted influenza by inactivated and live attenuated vaccines. N Engl J Med. 2006 Dec 14;355(24):2513-22. [PMID: 17167134]
Posted on September 24, 2008
