What is influenza (flu)?

Influenza, commonly called “the flu,” is a lung (respiratory) infection caused by the influenza virus.  Although someone with a mild case of flu may have symptoms similar to a cold, most cases of flu are more serious than the common cold. The flu virus changes slightly each year, so each year a new batch of vaccine
must be made.

When does flu occur?

Flu occurs in the United States most often in the winter. Flu-like symptoms
in summer months are usually due to other viruses.
Who gets the flu?
Anyone who has not been vaccinated with the current year’s flu vaccine
can get influenza. Each year in the United States, about 5-20 percent of
the population gets the flu.

What are the symptoms of flu?

The symptoms include fever, headache, dry cough, muscle aches, tiredness and weakness, with congestion in the nose, throat and lungs. Children may have nausea, vomiting and diarrhea, but these symptoms are uncommon in adults. The symptoms usually last about three to five days but in more serious infections, complications can occur and the illness may last longer.
How is the flu spread?
Influenza is very easy to spread from person-to-person when an infected person coughs or sneezes. This releases droplets from the nose and throat that contain the flu virus. The flu virus can also be spread when someone touches something that has virus on it, and then touches their nose, eyes or mouth. The flu can be spread from an infected person from the day before they get sick until about seven days after they first have symptoms, so they are contagious before they even know they are sick.
How can you prevent the flu?
The best way to avoid the flu is to get vaccinated each year during the flu season, if vaccine is available.  Vaccine is especially important for people who are most at risk for serious flu infections. Good health habits also go a long way toward preventing the spread of many diseases, including the flu.
Does past infection with influenza make a person immune?
No. Because viruses that cause flu change frequently, people who have had the flu or a flu shot in previous years may become infected with a new strain.
To locate a flu clinic in your area, please: http://www.flucliniclocator.org/

Article funded through the Asian Health Initiative of Tufts Medical Center