Respiratory syncytial virus can cause a viral respiratory infection that affects the lungs and respiratory tract in adults and children.

Respiratory syncytial virus (RSV) is common, and the infection tends to clear up in a week or two. “Syncytial” is pronounced “sin-SISH-ul.”

The infection can cause mild symptoms, similar to those of a common cold. However, severe cases can require hospitalization.

Serious cases are more common in very young children, older adults, and people with compromised immune systems. In the United States, RSV is a common cause of bronchiolitis and pneumonia in babies under 1 year old.

Fast facts about RSV

Here are some key points about the virus:

  • Most children have the infection by the age of 2 years.
  • The virus can spread through both direct and indirect contact with secretions from people with the infection.
  • It can survive on hard surfaces, such as tabletops and toys, for several hours.
  • Full recovery from the infection usually takes 1–2 weeks.
  • Treatment typically involves relieving the symptoms.

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RSV is a contagious virus that affects the respiratory system.

The Centers for Disease Control and Prevention (CDC) report that most children have exposure to RSV before they turn 2 years old. Among adults, the infection is most likely to affect older people and people with weakened immune systems.

The symptoms can be mild, like those of a common cold, but some people may have more severe symptoms, and bronchiolitis and pneumonia can develop.

According to the CDC, 1–2% of infants with RSV who are younger than 6 months need to spend time in a hospital for treatment.


In the U.S. and other countries with similar climates and seasons, RSV infections usually occur during the fall, winter, and spring.

However, this can vary from year to year. Also, the seasonality and severity may vary among different communities.

RSV is a contagious virus that spreads through droplets in the air or on surfaces. When a person with the infection coughs or sneezes, respiratory tract secretions containing the virus pass into the air.

RSV can survive for hours on surfaces such as tabletops, hands, and clothing, making it easy for the virus to pass from person to person.

The infection is usually contagious for 3–8 days, but in young children and people with weakened immune systems, the virus may be able to transmit for up to 4 weeks, even after the person’s symptoms disappear.

According to the CDC, early symptoms of RSV infection in infants and other children include a:

  • runny nose
  • reduced appetite
  • cough that may then turn to wheezing

Very young infants may have different symptoms from older children and adults, including:

  • irritability
  • reduced activity
  • reduced appetite
  • apnea, or pausing for breath while sleeping


RSV infections can be dangerous in infants, especially in those:

  • who were born preterm
  • younger than 6 months old
  • younger than 2 years old with lung, heart, or neuromuscular problems
  • who have weakened immune systems

However, most babies recover from RSV infections before the age of 2 years without any serious problems.

Learn more about RSV in infants here.

Children may commonly come into contact with RSV at school or daycare centers. They may then pass it on to family members.

Close contact, such as kissing, can transmit the virus. Also, if a person with RSV coughs or sneezes, infected droplets can pass on to others. In addition, touching surfaces that contain these droplets, then touching the face can transmit RSV.

People may develop symptoms of the infection 4–6 days after exposure to RSV.

These symptoms can include:

An infection with RSV is usually contagious for around 3–8 days. In infants under 6 months and people with weakened immune systems, the virus may continue to be contagious for up to 4 weeks, even when symptoms are no longer present.

People with no underlying medical conditions usually recover within 1 to 2 weeks.

Possible complications of RSV include:

Those at highest risk of complications or severe RSV symptoms include:

  • young infants, particularly those under 6 months
  • older adults, particularly those over the age of 65
  • infants born preterm
  • children with neuromuscular disorders
  • adults or children with weakened immune systems
  • people with congenital heart or chronic lung diseases

An RSV infection may also worsen certain conditions, including:

In severe cases, people may require treatment in a hospital. This enables health workers to:

  • monitor the symptoms, especially breathing problems
  • treat any dehydration
  • if necessary, offer advanced forms of treatment and medical support, such as additional oxygen

Hospitalization for RSV usually only lasts a few days.

Learn how to recognize dehydration in toddlers here.

Bronchiolitis is a lower respiratory tract infection that can result from RSV and is common in young children.

It involves infection of the lungs and inflammation of the airways, and it can cause:

  • a fever
  • a cough
  • a runny nose
  • a reduced appetite
  • increased mucus production
  • wheezing, or gurgling, bubbling sounds when the person breathes

Most cases are not serious, but if there are changes to a child’s breathing or feeding, if they have a high temperature, or if they seem tired or irritable, it is best to contact a doctor.

Call 911, or otherwise contact emergency medical services, if a child has:

  • a bluish tinge to their skin or lips
  • pauses in breathing
  • any difficulty breathing

Learn more about types of lower respiratory tract infection here.

If RSV symptoms are mild, a doctor does not usually use testing to distinguish between it and other viruses, such as other common cold viruses.

If the symptoms are severe or the risk associated with the infection is high, a doctor may use diagnostic tests.

To diagnose RSV, they take a full medical history and do a physical examination. The doctor may also take a mouth swab or order a blood test to check for the virus. They may also need a white blood cell count.

If RSV is severe, a doctor may request a CT scan, chest X-ray, or other tests to assess the person’s lung health. In infants, the doctor may take urine or blood samples to check for bronchiolitis or a urinary tract infection.

Most cases of RSV resolve without treatment in 1–2 weeks. In mild cases, the treatment aims to relieve the symptoms.

Self-care strategies may include:

  • staying home to avoid spreading the virus
  • staying comfortable and resting
  • drinking plenty of fluids
  • using a nasal suction bulb to relieve nasal stuffiness
  • using nasal saline drops
  • using a cool mist humidifier
  • taking pain relief medication, such as ibuprofen (Advil, Motrin) or acetaminophen (Tylenol) for a fever

It is important to avoid giving aspirin to children.

In severe cases of RSV, hospital treatment may include:

  • oxygen supplementation
  • breathing tubes, in cases of respiratory failure or severe apnea
  • intravenous fluids for hydration

Good hygiene practices, such as those below, can help prevent the spread of RSV.

  • Handwashing: This is important after coming into contact with anyone who has cold-like symptoms and before coming into contact with a child. Regular handwashing can also help children learn its importance. Each time, wash the hands with soap and water for at least 20 seconds.
  • Keeping surfaces clean: This involves regularly cleaning and disinfecting surfaces that people touch often, such as toys, tabletops, mobile devices, doorknobs, and handles.
  • Coughs and sneezes: Cover the mouth, preferably with a tissue or handkerchief, when coughing or sneezing. Or, sneeze into the elbow to avoid spreading infected droplets.

Learn how to wash the hands properly here.

Other tips include:

  • not sharing cups and utensils
  • limiting contact with people who have cold-like symptoms
  • limiting time spent in areas where RSV may be especially contagious, such as childcare settings, particularly in the fall, winter, and spring which are peak RSV seasons in the U.S.

For infants with a higher risk of RSV complications, doctors may recommend monthly RSV antibody injections, involving a drug called palivizumab, during the peak seasons.

RSV is common, especially in young children. It is a respiratory virus that can infect the throat, nose, lungs, and breathing passages. The virus can spread through droplets from coughing and sneezing.

Most people with the infection have mild symptoms, similar to those of a common cold. They usually recover within 2 weeks. However, it can be more dangerous for infants, older adults, and anyone with a weakened immune system.