Influenza (Flu) in Children

What is the flu in children?

Influenza (flu) is a very contagious viral infection that affects
the air passages of the lungs. It causes a high fever, body aches, a cough, and other
symptoms. It is one of the most severe and common viral illnesses of the winter season.
Most children are ill with the flu for less than a week. But some children have a more
serious illness and may need to be treated in the hospital. The flu may also lead to
lung infection (pneumonia) or death.

What causes the flu in a child?

The flu is caused by flu viruses. Flu viruses are divided into 3 types:

  • Influenza types A and B. These 2 types of viruses cause widespread illness (epidemics) almost every winter. They often lead to more people needing to go to the hospital, and more people dying from the flu. Public health officials focus on stopping the spread of types A and B. One of the reasons the flu remains a problem is because the viruses change (mutate) often. This means that people are exposed to new types of the viruses each year.
  • Influenza type C. This type of virus
    causes a very mild respiratory illness. . It uncommonly causes epidemics. It does not
    have the severe public health impact that influenza types A and B do.

A flu virus is often passed from
child to child through sneezing or coughing. The virus can also live for a short time
on surfaces. This includes doorknobs, toys, pens or pencils, keyboards, phones and
tablets, and countertops. It can also be passed through shared eating utensils and
drinking. Your child can get a flu virus by touching something that was touched by an
infected person, and then touching his or her mouth, nose, or eyes.

People are most contagious with the flu 24 hours before symptoms start, continuing while symptoms are most active. The risk of infecting others usually stops around day 7 of the illness. Because the flu can be spread before symptoms start, it’s easy to pick up a flu virus. This is true especially with children, who often touch many surfaces and then their mouth, nose, or eyes.

Which children are at risk for the flu?

A child is more at risk for the flu if he or she:

  • Is around people infected with the flu
  • Has not had the flu vaccine
  • Does not wash his or her hands after touching infected surfaces

Young children and children with certain underlying health conditions are at increased risk for a hospital stay or severe or complicated influenza infection. 

What are the symptoms of the flu in a child?

The flu is a respiratory disease, but it can affect the whole body. A child can become suddenly ill with any or all of these symptoms:

  • Fever, which may be as high as 103°F (39.4°C) to 105°F (40.5°C)
  • Body aches, which may be severe
  • Headache
  • Sore throat
  • Cough that gets worse
  • Tiredness
  • Runny or stuffy nose

In some cases, your child may also have symptoms such as:

  • Nausea
  • Vomiting
  • Diarrhea

Most children recover from the flu within a week. But they may still feel very tired for as long as 3 to 4 weeks.

It’s important to note that a cold and the flu have different symptoms:

Cold symptoms Flu symptoms
Low or no fever High fever
Sometimes a headache Headache in most cases
Stuffy, runny nose Clear nose, or stuffy nose in some cases
Sneezing Sneezing in some cases
Mild, hacking cough Cough, often turning severe
Mild body aches Severe body aches
Mild tiredness Extreme tiredness that can last weeks
Sore throat Sore throat in some cases

A cold is usually mild and often goes away after a few days. The flu can cause severe symptoms and lead to problems such as pneumonia and even death. The symptoms of the flu can be like other health conditions. Make sure your child sees his or her healthcare provider for a diagnosis.

How is the flu diagnosed in a child?

The healthcare provider will ask about your child’s symptoms and health history. He or she will give your child a physical exam. The symptoms are often enough to diagnose the flu. Your child’s provider may do other tests, depending on your child’s symptoms and overall health.