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What is H1N1 flu?

Novel (new) H1N1 influenza is a new strain of flu virus causing illness in people around the world. This virus was first detected in 2009.

The virus was originally referred to as swine flu because it was thought to have come from pigs (swine). However, the virus contains genes from swine, avian (bird), and human flu viruses. It is considered to be a new virus and is called new or novel H1N1 flu. Because this is a new virus, it may be easier to get sick from it.

How does it occur?

The H1N1 flu virus spreads from person to person the same way regular (seasonal) flu spreads. The virus is in mucus and saliva and is spread when someone coughs or sneezes. It can also spread when you touch something with the flu virus on it (like cups, doorknobs, hands and so forth) and then touch your mouth, nose, or eyes. The virus is not spread by eating pork or any other food.

People with H1N1 flu are contagious from 1 day before they start having symptoms to 7 days after the start of symptoms. Children might be contagious for as long as 10 days. This means that you can pass the flu to someone else before you even know you are sick and then for several days after you feel better.

No one really knows how long it will take to get sick after you have been around someone with H1N1 flu. It is probably 1 to 4 days and may be as long as 7 days.

What are the symptoms?

The main symptoms of H1N1 flu are similar to the symptoms of seasonal flu. They include:

  • fever of 100° F (37.8° C) or higher
  • cough
  • sore throat

Some people might also have:

  • runny or stuffy nose
  • body aches
  • headache
  • chills
  • tiredness

Children may have diarrhea or vomiting. About half of the people with the flu do not have a fever. Babies and young children may have fever and no energy. They may be sick even though they do not have a cough or sore throat.

How is it diagnosed?

If your child is so sick that they need to be in the hospital, your healthcare provider might test a sample of mucus from his nose to see if he has the H1N1 virus. The results may not be available for several days. The test is not routinely recommended. Instead, your healthcare provider will decide based on the symptoms, whether the child has been exposed to H1N1 flu, and if needed, a physical examination.

How serious is it?

Most cases of H1N1 flu are mild.

Some people are at higher risk for getting very sick:

  • children less than 5 years old
  • children and adolescents (less than 18 years old) who have to take aspirin every day (because having the flu might cause a condition called Reye's syndrome)
  • children who have chronic health problems (such as diabetes, or lung, heart, liver, kidney, or blood diseases)
  • children who have problems fighting an infection because of an immune system problem such as HIV or AIDS
  • children who live in group homes and other chronic-care places

If your child has any of the above risks, talk to your provider about the vaccines and any other treatment the provider may recommend.

How is it treated?

Flu is sometimes treated with antiviral medicine, but there may be a limited supply of the medicine. Antiviral medicine is not routinely recommended for children with H1N1 flu, and it is not recommended that children who have been exposed to the flu. Children who are very sick or who are at higher risk for getting very sick with the flu may be treated with antiviral medicine. Antiviral medicines include Tamiflu pills (oseltamivir) and Relenza inhalers (zanamivir). These drugs fight the flu by keeping the virus from growing in the body. They work best if they are started within the first 2 days of symptoms. However, they may be given at any time to a child who is very sick or at risk. Some viruses become resistant to these medicines, which means the medicines are then less effective against these viruses.

How long will the effects last?

Flu symptoms usually last 3 to 7 days.

Infection with the flu virus sometimes leads to other infections, such as ear and sinus infections. Pneumonia can also occur as a result of the flu.

The illness caused by the H1N1 virus is usually mild. However, some children become very sick. The virus has caused some deaths. H1N1 may be more severe in very young children or children with chronic medical conditions.

Is there a vaccine against H1N1 (swine) flu?

The best thing to do to help your child stay healthy is to have him get a seasonal flu vaccine and the H1N1 vaccine if he his age 6 months or older. Both vaccines are available as a shot or as a nasal spray. Both vaccines are made the same way and are very safe. Contact your health care provider or a local clinic for information on where you can take your child to get seasonal and H1N1 vaccines.

How can I take care of my child?

To take care of your child at home:

  • If a healthcare provider gives your child medicine to treat influenza, it is very important for your child to take all of the medicine exactly as prescribed. It should not be saved or shared with other people.
  • If your child has flu-like symptoms, he should STAY HOME until he has not had a fever for at least 24 hours (without having to take fever medicine).
  • Make sure your child gets plenty of rest.
  • Make sure your child drinks a lot of clear liquids. Water, broth, juice, and noncaffeinated drinks are best.
  • Give your child acetaminophen or ibuprofen to relieve headaches and muscle aches and to lower a fever. Children under 18 years of age should not take aspirin or products containing salicylate (such as Pepto-Bismol) because of the risk of Reye's syndrome, unless recommended by a healthcare provider.
  • The safest care for flu symptoms in children under 2 is a cool-mist humidifier and a suction bulb and saline solution to help clear away mucus from the nose.
  • Talk with your healthcare provider about whether you should give your child a decongestant. If your child's nose or sinuses become congested, a decongestant medicine may help you feel better. It may help prevent ear or sinus infections. However, not all children should take decongestants.
  • Do not give a child under age 4 any cough and cold medicines unless you are told to do so by your healthcare provider. Children over 6 years old may be given cough drops or hard candies to relieve a sore throat or cough.

What can I do to prevent spreading the flu if my child is sick?

If your child is sick, you can help protect others if you:

  • Keep your children home from daycare or school if they are sick. Your child should avoid contact with other people except to get medical care. If he must leave the house, think about having him wear a face mask if you have one.
  • Teach your child to cover his or her nose and mouth with a tissue when coughing or sneezing. If he doesn't have a tissue, teach him to cough or sneeze in to his upper sleeve instead of his hands. Make sure your child throws the tissue in the trash after using it, and then washes his or her hands.
  • Clean your child's hands often with soap and water or an alcohol-based hand rub, especially after using tissues or coughing or sneezing.
  • You don't need to clean your sick child's linens, eating utensils, cups, and dishes separately, but don't share them without washing them first.
  • Wash linens like clothes, bed sheets and towels with laundry soap and tumble dry on a hot setting. Don't "hug" laundry as you carry it to be washed. Clean your hands right after handling dirty laundry.
  • If you are concerned about mild symptoms, call your healthcare provider. Do not go to the office or clinic without calling first. In many cases you can manage his symptoms at home.

What can I do to keep my child from getting the flu if he is not sick?

  • Teach children to wash their hands often with soap and water. Wash for 20 seconds (long enough to sing the whole "Happy Birthday" song) or use an alcohol-based hand cleaner.
  • Teach children to avoid touching their eyes, noses, or mouths when out in public.
  • Avoid close contact with people who are sick. Keep your child at least 6 feet away if you can.
  • Make sure that your child gets plenty of sleep, is physically active, drinks plenty of fluids, and eats healthy food.
  • In areas where H1N1 flu has occurred, consider staying away from shopping malls, movie theaters, or other places where there are a lot of people. If you have to be in a crowded setting, spend as little time there as possible.
  • Keep surfaces clean (especially bedside tables, surfaces in the bathroom, and toys for children). Some viruses and bacteria can live 2 hours or more on surfaces like cafeteria tables, doorknobs, and desks. Wipe them down with a household disinfectant according to directions on the label.
  • It has not been shown that face masks will keep you from getting the flu if you are around others who have the flu. Face masks are more useful if they are worn by people who are sick, to keep them from spreading the virus.

When should I seek emergency medical care for my child?

If your child has any of the following warning signs, get emergency medical care:

  • Trouble breathing
  • Not drinking enough fluids, not urinating or no tears when they cry.
  • Fever with a rash
  • Severe vomiting
  • Seizures
  • The child is very difficult to wake up or extremely irritable
  • Flu symptoms that get better and then return with fever and worse cough

For more information contact the Centers for Disease Control or visit their Web site at