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Flu (Influenza)

What is the flu?

The flu (influenza) is a contagious respiratory disease caused by flu viruses. It is spread from person to person by coughing or sneezing. It can also be spread by touching contaminated surfaces.

Symptoms of flu include fever* or feeling feverish/chills, cough, sore throat, runny or stuffy nose, muscle or body aches, headache, and tiredness.  Nausea, vomiting, and diarrhea also can occur but are more common in children than adults.  Young children, senior citizens, and people who have chronic health conditions are at risk for serious complications. These complications can include pneumonia, ear infections, sinus infections, dehydration, worsening of chronic medical conditions, and death.

*It’s important to note that not everyone with flu will have a fever.

Who is at risk?

 

Flu is common throughout the world. The flu season lasts from October through May in the Northern Hemisphere and from April through September in the Southern Hemisphere. In tropical countries, flu can be spread year-round.

International travel does not increase your risk of getting the flu, but travel to tropical countries or countries in the Southern Hemisphere and contact with people from these places can put you at risk for the flu outside the regular flu season in the United States.

What can travelers do to prevent the flu?

Get a flu vaccine:

  • CDC recommends a yearly flu vaccine as the first and most important step in protecting against flu viruses.
  • A flu vaccine protects against the three viruses that research suggests will be most common.
  • Everyone 6 months of age and older should get a flu vaccine as soon as the current season’s vaccines are available.
  • The flu vaccine is available as either a short or a nasal spray.
  • Vaccination of high risk people decreases their risk of severe flu illness.
    • People at high risk for developing flu-related complications include:
      • children younger than 5, but especially children younger than 2 years old
      • Adults 65 years of age and older
      • Pregnant women
      • American Indians and Alaskan Natives
      • People who have medical conditions such as asthma, lung disease or heart disease
  • See Vaccine Information Statements (VIS) for more information:

Stop the spread of germs:

  • Try to avoid close contact with sick people.
  • If you get sick with flu-like illness, CDC recommends that you stay home for at least 24 hours after the fever is gone except to get medical care or for other necessities. The fever should be gone without the use of a fever-reducing medicine.
  • While sick, limit contact with others as much as possible to keep from infecting them.
  • Cover your nose and mouth with a tissue when you cough or sneeze. Throw the tissue in the trash after you use it.
  • Wash your hands often with soap and water. If soap and water are not available, use an alcohol-based hand sanitizer.
  • Avoid touching your eyes, nose and mouth. Germs spread this way.
  • Clean and disinfect surfaces and objects that may be contaminated with germs like the flu.

If you feel sick and think you may have the flu:

  • Talk to your doctor or nurse if you feel seriously ill, especially if you have a fever.
  • Avoid contact with other people while you are sick
  • Take flu antiviral drugs if your doctor prescribes them.
    • If you get the flu, antiviral drugs can treat your illness.
    • Antiviral drugs are different from antibiotics. They are prescription medicines (pills, liquid or an inhaled powder) and are not available over-the-counter.
    • Antiviral drugs can make illness milder and shorten the time you are sick. They may also prevent serious flu complications. For people with high risk factors,  treatment with an antiviral drug can mean the difference between having a milder illness versus a very serious illness that could result in a hospital stay.
    • Studies show that flu antiviral drugs work best for treatment when they are started within 2 days of getting sick, but starting them later can still be helpful, especially if the sick person has a high-risk health or is very sick from the flu. Follow your doctor’s instructions for taking this drug.

Traveler Information

Clinician Information

 
Contact Us:
  • Centers for Disease Control and Prevention
    1600 Clifton Rd
    Atlanta, GA 30333
  • 800-CDC-INFO
    (800-232-4636)
    TTY: (888) 232-6348
  • Contact CDC-INFO
USA.gov: The U.S. Government's Official Web PortalDepartment of Health and Human Services
Centers for Disease Control and Prevention   1600 Clifton Rd. Atlanta, GA 30333, USA
800-CDC-INFO (800-232-4636) TTY: (888) 232-6348 - Contact CDC–INFO
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