Respiratory Syncytial Virus

In this factsheet:
• The Facts on Respiratory Syncytial Virus
• Causes of Respiratory Syncytial Virus
• Symptoms and Complications of Respiratory Syncytial Virus
• Diagnosing Respiratory Syncytial Virus
• Treating and Preventing Respiratory Syncytial Virus

The Facts on Respiratory Syncytial Virus

Most infants are exposed to the respiratory syncytial virus (RSV) by their second birthday. 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.

Causes of Respiratory Syncytial Virus

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 of Respiratory Syncytial Virus

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).

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.

Continued... 1 | 2 | Next