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What is respiratory syncytial virus (RSV)?

 A man holds a smiling baby

This virus generally only causes coldlike symptoms. But in young children and people with weakened immune systems it may sometimes lead to more serious respiratory trouble.

Kids seem to have more than their share of runny noses. In fact, children have an average of six to eight colds each year.

The respiratory syncytial virus (RSV) is one of more than 200 viruses that may cause children to develop a cold. Usually RSV causes the same mild symptoms as other cold viruses, such as a runny nose, cough and low-grade fever.

But RSV can also cause more serious infections. RSV is the most common cause of pneumonia and bronchiolitis (inflammation of the small airways in the lung) in children under 1 year old in the U.S., according to the Centers for Disease Control and Prevention.

How RSV spreads

RSV passes between people via physical contact or infected droplets that can travel through the air when they sneeze or cough. RSV can also live for several hours on surfaces such as countertops, tables, playpens or unwashed hands.

Children at risk

Anyone can get the common cold from RSV. But some people who develop the infection are more vulnerable to serious respiratory problems. These groups include:

  • Babies born preterm (before 37 weeks of pregnancy are completed).
  • Infants 6 months and younger.
  • Children with other health conditions, such as chronic lung disease or serious heart conditions.
  • Children with weakened immune systems.
  • Adults 65 and older.

When to get help

According to the American Lung Association and the American Academy of Pediatrics (AAP), you should call your doctor if your baby develops any of the following symptoms:

  • Difficult or rapid breathing.
  • Wheezing.
  • Signs of dehydration—dry mouth, dry diapers for several hours, or fewer tears when crying.
  • Flaring of the nostrils.
  • Irritability and restlessness.
  • Fever or worsening cough.
  • Extreme tiredness, especially during times your child would normally be active.

Seek immediate medical attention if the child has a blue or gray tongue, lips or skin.

Treatment for mild infections may involve relieving symptoms. For example, a doctor may recommend acetaminophen to reduce your child's fever. (Remember, you should never give aspirin to a child who has a fever—it can cause a serious illness known as Reye's syndrome.)

More serious illness may require oxygen therapy or medications.

Staying healthy

The best way to prevent the spread of RSV is to wash your hands and your child's hands frequently with soap and warm water, according to the AAP. Take special care during winter, when RSV infections are most common. A child with RSV can be contagious for up to four weeks after symptoms go away.

You can also teach older children to:

  • Cover their mouths and noses with tissues when they cough or sneeze.
  • Cough or sneeze into their upper sleeves if they don't have a tissue.
  • Throw used tissues into the garbage.

And remember to set a good example by washing your hands regularly and covering your mouth and nose when you sneeze or cough.

Reviewed 8/9/2022

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This information is provided for educational purposes only. Individuals should always consult with their healthcare providers regarding medical care or treatment, as recommendations, services or resources are not a substitute for the advice or recommendation of an individual's physician or healthcare provider. Services or treatment options may not be covered under an individual's particular health plan.