Medical Conditions - Respiratory Syncytial Virus

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Respiratory Syncytial Virus


The Facts

Most infants are exposed to the respiratory syncytial virus (RSV) by their second birthday, and almost all children are infected by the age of 4. RSV can cause a serious lung infection in infants and younger children and is more common in premature babies and infants or younger children with health problems, such as heart or lung disease.

Seniors and adults with heart or lung problems may also experience a severe infection. People with a weakened immune system are also at risk. RSV does not cause such a serious infection for healthy children and adults, who may experience symptoms similar to the common cold.

Even though people, including infants, develop antibodies (immune defenses) against the virus after an infection, it appears the virus is able to reinfect individuals throughout their lifetime. In cases of reinfection, symptoms are usually less severe than the first infection.


Viruses are biological agents made of genetic materials and proteins that are able to infect a host (a living organism) and replicate. RSV can enter the body through the eyes, nose, or mouth. Physical contact, kissing, or inhaling air droplets containing the virus (from an infected person’s cough or sneeze) all increase the possibility of acquiring the infection.

The virus particles can live for hours on surfaces, such as keyboards, toys, and doorknobs so you can also become infected by touching your eyes, nose, or mouth after coming into contact with an infected surface.

Much like the flu, which is also caused by a virus, RSV is a seasonal condition. RSV appears to spread most rapidly from autumn to spring. As children enter daycare or interact with other children, RSV moves easily from one child to the next.

Symptoms and Complications

RSV causes different symptoms and complications in different people. Signs and symptoms of the condition generally occur 4 to 6 days after exposure to the virus.

The symptoms of severe infection include:

  • coughing
  • high fever
  • low oxygen level in blood (skin may appear bluish)
  • shallow or rapid breathing
  • wheezing or difficulty breathing

Medical attention is most important for infants under 6 months of age, those born prematurely, or infants with heart or lung problems. These infants may require hospitalization because the infection could progress to the point of requiring specialized machines to assist breathing (mechanical ventilation). You should also see a doctor for RSV if you are over the age of 65 or have a weakened immune system.

The symptoms of a mild infection are similar to the symptoms of a cold and do not usually lead to hospitalization. The symptoms of mild infection may include:

  • congestion
  • cough
  • headache
  • runny nose
  • sore throat

Possible complications include ear infections, sinus infections, pneumonia, or in severe cases, respiratory failure.

Making the Diagnosis

Doctors use a number of tests to diagnose RSV. Physical examination including listening to the lungs for abnormal sounds, and looking at the colour of the skin is routine. If pneumonia is suspected, X-rays of the chest can provide more information.

The doctor may also take a sample of the mucus or a throat swab to identify the virus. Blood tests may help provide a diagnosis and could rule out other possible infections.

Treatment and Prevention

Since the condition is caused by a virus, treatment focuses on relieving the symptoms while the infection is present and treating complications should they occur. With time, the virus will disappear by itself.

Medications such as acetaminophen* or ibuprofen can help reduce a fever or relieve discomfort. Complications such as ear infections, sinus infections, or pneumonia can be treated with antibiotics if they are caused by bacteria. Antibiotics destroy the bacteria, but they have no effect on RSV.

When an infected person is having severe problems breathing, inhaling a mist of medication into the lungs can help open the airways. In addition, a supply of oxygen or a breathing machine may help infants who are not breathing easily on their own.

Until RSV vaccination is widely available, your doctor may suggest palivizumab as a preventative measure. It is given in the first 2 years of life to premature babies and young children with heart or lung problems who may be at an increased risk of developing RSV. It is an intramuscular injection given monthly during the high-risk season.

While it may not be easy to completely prevent RSV, there are some simple things you and your family can do to reduce the risk of RSV and prevent its spread:

  • Practice good hygiene by washing your hands frequently, especially before holding or touching an infant.
  • Keep infants away from people who have a cold, fever, or other infectious conditions.
  • Clean your home, including children’s toys, to keep it free from germs.
  • Do not smoke in the home, as exposure to second-hand smoke increases a person’s chances of catching RSV.
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