Respiratory Syncytial Virus (RSV)

What is respiratory syncytial virus (RSV)?

RSV is the most common cause of bronchiolitis (inflammation of the small airways in the lungs) and pneumonia in babies. It is an illness that often occurs in yearly outbreaks in communities, school classrooms, and day care centers. In the United States, RSV is more common in winter and spring months.

What causes respiratory syncytial virus (RSV)?

RSV is spread from respiratory secretions through close contact with infected people or contact with contaminated surfaces or objects. Infection can occur when infectious material contacts mucous membranes of the eyes, mouth, or nose, and possibly through the inhalation of droplets generated by a sneeze or cough. The incubation period (time from exposure to symptoms) is about four to six days.

Who is affected by respiratory syncytial virus (RSV)?

RSV can affect a person of any age, although it is most common in babies between 2 and 8 months old. Most babies have been infected at least once by the time they are 2 years old. Babies can also be reinfected with the virus. Recurrence throughout life is common. Babies born prematurely or with chronic lung disease are at increased risk of developing more severe illness.

Why is respiratory syncytial virus (RSV) a concern?

In babies born prematurely, or who have certain heart, lung, and neuromuscular diseases, infection with the virus can lead to severe respiratory illness and pneumonia, and may become life-threatening. RSV in infancy may be related to development of asthma later in childhood.

What are the symptoms of respiratory syncytial virus (RSV)?

The early phase of RSV in infants and young children is often mild, somewhat like a cold. In children younger than 3, the disease may progress into the lower airways and cause coughing and wheezing. In some, the infection progresses to a severe respiratory disease requiring hospitalization to help the child breathe.

The following are the most common symptoms of RSV. However, each baby may experience symptoms differently. Symptoms may include:

  • Runny nose

  • Fever

  • Cough

  • Apnea (short periods without breathing)

  • Listlessness

  • Poor feeding

  • Wheezing

  • Retractions (pulling in) of the chest wall

  • Rapid breathing; turning blue around the lips 

The symptoms of RSV may resemble other conditions or medical problems. Always consult your baby's primary care provider for a diagnosis.

How is respiratory syncytial virus (RSV) diagnosed?

Diagnosis is sometimes difficult because the symptoms of RSV can resemble other infections. Illness in other family members, other babies in the hospital nursery, or the time of year may provide clues. In addition to a complete medical history and physical examination of your child, a test (nasal swab or nasal wash) of the baby's respiratory secretions may show the presence of a virus.

What is the treatment for respiratory syncytial virus (RSV)?

Specific treatment for RSV will be determined by your baby's primary care provider based on:

  • Your baby's age, overall health, and medical history

  • The extent of the condition

  • Your baby's tolerance for specific medications, procedures, or therapies

  • Expectations for the course of the condition

  • Your opinion or preference

There are no medications used to treat the virus itself. Care of a baby with RSV involves treating the effects of the virus on the respiratory system. Because a virus causes the illness, antibiotics are not useful.

Treatment may include:

  • Supplemental oxygen

  • Intravenous fluids (to prevent dehydration)

  • Tube feedings (if the baby has difficulty sucking)

  • Bronchodilator medications (to open the airways)

  • Antiviral medications (for very sick or high-risk babies)

How can respiratory syncytial virus (RSV) be prevented?

The CDC and the American Academy of Pediatrics recommend that babies at high risk for RSV receive the medication palivizumab (Synagis) to protect them against the serious complications of the illness. High-risk babies include those born prematurely and those with heart, lung, or neuromuscular diseases. Palivizumab is a monoclonal antibody that is usually given monthly during the RSV "season" from late fall through spring.

Palivizumab is not a vaccine and does not prevent the virus. But it does lessen the severity of the illness and may help shorten the hospital stay.

In addition, contacts with your baby should wash their hands with warm soapy water prior to holding your baby. Keep your baby away from tobacco smoke as well as crowded areas like malls.


Reviewed by Christopher W. Drexler, DO, FAAP, Naline Lai, MD, FAAP

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