Respiratory Syncytial Virus (RSV)
Respiratory syncytial virus (RSV) is a virus that causes infections of the lungs and respiratory tract. It's so common that most children have been infected with the virus by age 2. Respiratory syncytial virus can also infect adults.
In adults and older, healthy children, the signs and symptoms of respiratory syncytial virus typically mimic the common cold. However, it's the leading cause of serious respiratory infection in infants and children. Respiratory syncytial virus may be severe and may require hospitalization, especially in infants under 6 months of age, children with underlying conditions — such as congenital heart or lung disease — and children who were born prematurely. Respiratory syncytial virus infection can also become serious in older adults and adults with heart and lung diseases.
Common-sense precautions can help prevent the spread of respiratory syncytial virus.
Respiratory syncytial virus enters the body though your eyes, nose or mouth. It spreads easily when infectious respiratory secretions — such as those from coughing or sneezing — 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 your 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 Factor :
By age 2, most children will have been infected with respiratory syncytial virus. Children who attend child care centers or who have siblings who attend school are at a higher risk of infection. So are infants who are exposed to high levels of air pollution or cigarette smoke. Susceptibility also is greater during the peak RSV season, which typically begins in the fall and ends in the spring.
People at increased risk of severe — sometimes life-threatening — infections include :
- Infants younger than 6 months of age
- Children with underlying conditions such as congenital heart or lung disease
- Children with weakened immune systems, such as those undergoing chemotherapy or transplantation
- Children who were born prematurely
- Older adults
- Adults with congestive heart failure or chronic obstructive pulmonary disease
When to seek medical advice :
Most cases of respiratory syncytial virus infection aren't life-threatening. Still, seek medical advice for a child, older adult or other person at high risk who experiences any of its signs and symptoms. Also seek immediate medical attention if your child experiences difficulty breathing, runs a high fever or turns blue in color.
Signs and symptoms of respiratory syncytial virus typically appear about four to six days after exposure to the infection. In adults and children older than 3, respiratory syncytial virus usually causes mild cold-like signs and symptoms similar to those present during an upper respiratory infection. These include :
- Congested or runny nose
- Dry cough
- Low-grade fever
- Sore throat
- Mild headache
- A general feeling of unease and discomfort (malaise)
In children younger than 3 years of age, RSV can lead to a lower respiratory tract illness such as pneumonia or bronchiolitis — an inflammation of the small air passages in the lungs. Signs and symptoms may include:
- High fever
- Severe cough
- Wheezing — a high-pitched noise that's usually heard on breathing out (exhaling)
- Rapid breathing or difficulty breathing, which may make the child prefer to sit up rather than lie down
- Bluish color of the skin due to lack of oxygen
Infants are most severely affected by respiratory syncytial virus. They may markedly draw in their chest muscles and the skin between their ribs, indicating that they are having trouble breathing, and their breathing may be short, shallow and rapid. Or they may not show any signs of a respiratory tract infection, but will eat poorly and be unusually lethargic and irritable.
Most children and adults recover from the illness in eight to 15 days. But in young babies, infants born prematurely, or infants or adults who have chronic heart or lung problems, the virus may cause a more severe — occasionally life-threatening — infection that requires hospitalization.
Your doctor may suspect respiratory syncytial virus based on a physical exam and the time of year of the infection. During the exam, he or she may listen to the lungs with a stethoscope to check for wheezing or other abnormal sounds, which may help determine why there is difficulty breathing. A painless skin test may be done to check whether the level of oxygen available in the bloodstream is lower than usual. Your doctor may also conduct blood tests to check white cell counts or to look for the presence of viruses, bacteria or other organisms.
Chest X-rays may be used to check for pneumonia. In addition, your doctor may collect respiratory secretions from your nose to test for the virus in a lab.
Respiratory syncytial virus is the most common cause of respiratory illness in infants and young children. But it can be serious — especially for babies younger than 6 months old, babies that are born prematurely, and babies with congenital heart or lung disease.
Each year, up to 125,000 infants in the United States are hospitalized with severe RSV, and a small percentage die of the infection. Of infants and young children experiencing their first RSV infection, many also experience symptoms of bronchiolitis and pneumonia. Middle ear infections — which occur when bacteria infiltrate the space behind the eardrum — are another complication. There may also be a link between severe respiratory syncytial virus and the chance of developing asthma later in life.
Once a person has been infected with respiratory syncytial virus, it's common to occasionally experience a recurrence of RSV throughout life. Subsequent infections typically aren't as severe, but in older adults or people with chronic heart or lung disease, it can be serious and, in some cases, fatal.
Antibiotics, which doctors prescribe to treat bacterial infections, are of no use against RSV because it's a viral infection. However, your doctor may prescribe antibiotics if there's a bacterial complication, such as middle ear infection or bacterial pneumonia. Otherwise, he or she may recommend an over-the-counter medication such as acetaminophen (Tylenol, others) or ibuprofen (Advil, Motrin, others), which reduces fever but won't cure the infection or make it go away sooner.
In cases of severe infection, hospitalization may be necessary to provide intravenous (IV) fluids and humidified oxygen. Hospitalized infants and children may also be hooked up to mechanical ventilation — a breathing machine — to ease breathing.
In some severe cases, a nebulized bronchodilator such as albuterol (Proventil, Ventolin) may be used to relieve wheezing. This medication opens air passages in the lungs. Nebulized means it's administered as a fine mist that you breathe in. Occasionally, a nebulized form of ribavirin (Rebetol), an antiviral agent, may be used. Your doctor may also recommend an injection of epinephrine or a form of epinephrine that can be inhaled through a nebulizer (racemic epinephrine) to relieve symptoms of a respiratory syncytial virus infection.
No vaccine exists for respiratory syncytial virus. But common-sense precautions can help prevent the spread of this infection :
- Wash your hands frequently. Do so particularly before touching your baby, and teach your children the importance of hand washing.
- Avoid exposure. Limit your infant's contact with people who have fevers or colds.
- Keep things clean. Make sure countertops are clean in the kitchen and bathrooms, especially when someone in your family has a cold. Discard used tissues right away.
- Don't share drinking glasses with others. Use your own glass or disposable cups when you or someone else is sick.
- Don't smoke. Infants who are exposed to tobacco smoke have a higher risk of contracting RSV and potentially more severe symptoms.
- Wash toys regularly. Do this especially when your child or a playmate is sick.
In addition, there is a medication called palivizumab (Synagis) that can help protect children under age 2 who are at high risk of serious complications when they get RSV, such as those born prematurely or with congenital heart or lung disease.
Synagis works by providing the necessary antibodies to protect against respiratory syncytial virus. It requires a monthly injection into the muscle tissue of the thigh during the peak RSV season, beginning in the fall and continuing for about five months. Injections are repeated every year until the child is no longer at high risk. The medication doesn't interfere with childhood vaccines.
Use of this treatment decreases the frequency and length of hospitalization for respiratory syncytial virus infections. But the high cost of the medication limits its use to those at highest risk of complications from RSV infections. The medication isn't helpful in treating RSV infection once it has developed. Talk to your doctor if you think your child may qualify for this treatment.
Scientists are working to find a vaccine that may prevent respiratory syncytial virus infections not only in infants but also in older adults and high-risk adults.