Respiratory syncytial virus (RSV) is a virus that causes infections of the lungs and respiratory tract. It is so common that most children have been infected with the virus by age 2. In adults and older, healthy children, the symptoms of respiratory syncytial virus are mild and typically mimic the common cold. Infection with respiratory syncytial virus can be severe in some cases, especially in premature babies and infants with underlying health conditions. RSV can also become serious in older adults, adults with heart and lung diseases, or anyone with a very weak immune system.



Infants may markedly draw in their chest muscles and the skin between their ribs, indicating that they are having trouble breathing. They may also cough or show few signs of a respiratory tract infection, but will eat poorly and be unusually lethargic. The symptoms of RSV infection typically appear about four to six days after exposure to the virus and are similar to those of a bad cold. These include:

  • Congested or runny nose
  • Dry cough
  • Low-grade fever
  • Sore throat
  • Mild headache

In more severe case, the RSV can lead to pneumonia or bronchiolitis. Those symptoms may include:

  • Fever
  • Severe cough
  • Wheezing
  • Rapid breathing or difficulty breathing
  • Bluish color of the skin due to lack of oxygen



Respiratory syncytial virus enters the body through the eyes, nose or mouth. It spreads easily when infectious respiratory secretions are inhaled or passed to others through direct contact, such as shaking hands. The virus can also live for hours on objects such as countertops and toys. Touch the mouth, nose or eyes after touching a contaminated object, and you're likely to acquire the virus. An infected person is most contagious in the first few days after infection, but respiratory syncytial virus may spread for up to a few weeks after the start of infection.


Risk Factors

People at increased risk of severe infections include:

  • Infants younger than 6 months of age
  • Younger children, especially under 1 year of age, who were born prematurely or who have an underlying condition, such as congenital heart or lung disease
  • Children with weakened immune systems, such as those undergoing chemotherapy or transplantation
  • Infants in crowded child care settings
  • Older adults
  • Adults with asthma, congestive heart failure or chronic obstructive pulmonary disease
  • People with immunodeficiency, including those with certain transplanted organs, leukemia or HIV/AIDS



Complications of respiratory syncytial virus include:

  • Hospitalization when the virus infection causes severe illness;
  • Pneumonia or bronchiolitis;
  • Middle ear infection;
  • Asthma;
  • Recurring infections;



No vaccine exists for respiratory syncytial virus. But common-sense precautions can help prevent the spread of this infection:

  • Wash the hands frequently;
  • Avoid exposure;
  • Keep things clean;
  • Not to share drinking glasses with others;
  • Avoid smoking in front of infants;
  • Wash toys regularly