What is influenza?

Influenza, or “the flu”, is a very contagious respiratory illness caused by influenza A or B viruses. These viruses are typically more active in the winter or early spring, but can be seen any time of the year. Type A and its various mutations are generally responsible for major flu epidemics seen every few years. Type B is less common and generally results in milder cases of the flu. Vaccines for flu contain both Type A and Type B varieties.

The flu virus is spread between people by respiratory secretions making people who spend time in close contact with others particularly at risk. This includes but is not limited to daycares, schools, college dormitories, military barracks, offices, prisons, and nursing homes. Flu spreads through droplets of respiratory secretions in the air when someone coughs or sneezes, by sharing drinks or utensils, or handling items contaminated by infected persons. Symptoms can start 1-4 days after contact with the infected person. If you have the flu, you are contagious generally one day BEFORE onset of symptoms and up to 5-7 days after illness starts.

What are the symptoms of the flu?

Symptoms of the flu can be any or all of the following: fever, chills, cough, sore throat, body aches, headache, fatigue, lack of appetite, and runny or stuffy nose. Symptoms can occur suddenly. Vomiting and diarrhea is less common in the flu, and if present, is more likely in children than adults.

How is the flu different from a cold?

Flu symptoms usually come on suddenly, whereas cold symptoms may take several days to fully develop. Some patients will describe it as “I feel like I was suddenly hit by a truck.” There is abrupt onset of fever, which is usually high, headache, fatigue, and body aches, which is less pronounced in colds. Cough is usually more pronounced at the onset of flu, where as in a cold, nasal congestion occurs earlier and cough later.

What is the stomach flu?

The “stomach flu” is actually not the flu at all. It is a layman’s term for viral gastroenteritis, which is fever, vomiting, and diarrhea. There is no treatment for the “stomach flu” except fluids and medicines to treat the symptoms. It is self-limited and usually resolves on its own in a few days with supportive care such as fluids and rest.

Is there a test for the flu?

Most cases of the flu during the peak influenza times can be diagnosed based on symptoms and exam alone without a definitive test. If it unclear if you have the flu there are two tests available. Some doctors have a rapid test which is done with a swab taken from the nose and then tested in the office. It takes about 15-30 minutes to obtain the results. A long term culture of the flu can also be done, but is sent to the lab and may take up to several days to obtain the results. This test is usually done on hospitalized patients or when it is important to know the type of flu that you have. Sometimes your doctor will do the test to help decide whether or not to prescribe the anti-viral medication (see below).

How long will I be sick?

Most patients will recover from the flu without any serious complications in 1-2 weeks. However some patients are at risk for more serious complications despite advances in flu prevention and treatment. This includes infants, the elderly, pregnant women, and people with chronic diseases such as diabetes, heart disease, lung disease, and HIV/AIDS. The CDC estimates that 3,000-49,000 people die from flu in the U.S. each year. Complications include pneumonia, ear infections, sinus infections, dehydration, and worsening of chronic medical conditions such as asthma or congestive heart failure.

How can I treat the flu at home?

If you think you have the flu, STAY HOME AND AVOID OTHERS. This is the only way to prevent spread of the disease. You should rest in bed and drink plenty of fluids, even if you don’t feel like it. You can take acetaminophen or ibuprofen over-the-counter to relieve fever, aches, and pains. Do NOT give aspirin to anyone under 18 with a viral infection like the flu as it can cause a potentially fatal reaction called Reyes’ syndrome. If you must contact others, you should wear a mask to prevent the spread of illness. If you go to the doctor’s office or the hospital they may ask you to wear a mask until it is determined you do not have the flu, or until you leave the office.

Are there prescription flu medicines?

There are anti-viral medications that your doctor can prescribe if he or she thinks you will benefit from them. These medicines do not cure the flu but rather shorten the duration and severity of flu symptoms. These medicines work best if they are given as early into the illness as possible, within 24-48 hours. They are most often given to patients at risk for the complications of the flu (see below). They may not be given to otherwise young and healthy patients. Your doctor will decide if these medicines will benefit you. Your doctor may also prescribe medicines to help with the symptoms of flu such as cough medicine. Antibiotics are not prescribed for the flu as it is a viral, not a bacterial illness. Antibiotics may be prescribed for the complications of the flu such as pneumonia, ear, or sinus infections.

When should you see a doctor?

If you or your doctor think you may benefit from the anti-viral flu medication, it is important to see the doctor sooner rather than later as it needs to be started within 48 hours of the onset of symptoms. Patients who have chronic medical conditions such as heart disease, asthma, COPD/asthma/emphysema, diabetes, or HIV/AIDS should call their doctor as soon as symptoms appear. If you have had the flu for 3-7 days and then get suddenly worse you should also see your doctor. Worsening of symptoms could mean that you have developed a complication of the flu. Symptoms of complications include: return of fever after it has been gone for a day or two, your fever lasts more than 3 days, you have trouble breathing, or you wheeze when breathing. If you have shortness of breath or can’t breathe or have a headache with a stiff neck you should call 911 and go to the hospital.

How can I prevent the flu?

The best way to prevent the flu is to get the flu vaccine every year. Although this is not always 100% effective, even if you get the flu you will likely not get as sick as someone who did not get the vaccine. The vaccine takes about 2 weeks to be fully effective, so you should get vaccinated as soon as possible, before influenza starts spreading in your community. Whether you are vaccinated or not, you should wash your hands often with soap and water or use alcohol based hand sanitizers. Staying away from people you know are sick with a respiratory illness is also a good idea.

Where can I get more information?

www.cdc.gov/flu

http://www.uptodate.com/patients/contents/search?search=influenza&sp=3&x=0&y=0

http://www.webmd.com/cold-and-flu/flu-guide/default.htm