H1N1 (swine) influenza Health Article

Definition

The H1N1 virus (swine flu) is a new flu virus strain that is causing illnesses in humans worldwide.

In June 2009, the World Health Organization declared a worldwide swine flu pandemic.

Alternative Names

Swine flu; Influenza A

Causes, incidence, and risk factors

Earlier forms of the H1N1 virus were found in pigs. Over time, the virus changed (mutated) and can now infect humans. Because H1N1 is a new virus in humans, your immune system cannot fight the virus very well. As a result, it has spread quickly around the world.

The largest number of H1N1 flu cases have occurred in people ages 5 - 24. Few cases, and no deaths, have been reported in people older than age 64.

The H1N1 flu virus can spread from person to person when:

• Someone with the flu coughs or sneezes into air that others breathe in.
• Someone touches a door knob, desk, computer, or counter with the H1N1 germs on it and then touches their mouth, eyes, or nose.
• Someone touches mucus of a child or others while taking care of them when they are ill with the H1N1 flu virus

You CANNOT get H1N1 flu virus from eating pork or any other food, drinking water, swimming in pools, or using a hot tubs or saunas.

Symptoms

Symptoms of H1N1 flu infection in humans are similar to classic flu-like symptoms, which might include:

• Fever above 100.4 °F
• Cough
• Sore throat
• Runny or stuffy nose
• Headache
• Chills
• Muscle aches and fatigue
• Diarrhea
• Vomiting

Signs and tests

If you think you have been exposed to H1N1 influenza, call your health care provider before your visit. The medical staff may want to take proper precautions to protect themselves and other patients during your office visit.

Because the H1N1 flu has become widespread, most people do not need to be tested for it when they have symptoms.

Your doctor may test you for the H1N1 flu virus by swabbing the back of the inside of your nose if:

• You are at high risk for flu complications.
• Others at high risk of flu complications have been in close contact with you.
• You are very sick.

Your doctor may:

• Look in your mouth, throat, nose, and ears
• Listen to your lungs
• Perform a chest x-ray