Respiratory syncytial virus (RSV)

Respiratory syncytial virus (RSV) is a major cause of respiratory infection in infants and children.


Causes/associated factors
Respiratory syncytial virus is highly contagious. In fact, nearly all children in the United States have been infected with the virus by age 3. RSV can also affect older children and adults, but it's usually less severe. Community outbreaks are most common during the winter and spring.
For most healthy children, RSV simply causes cold-like symptoms for a few days. However, RSV can cause a serious respiratory illness for newborns, infants and a small group of children at high risk -- including kids who have heart disease, lung disease, compromised immune systems or other medical conditions, as well as those under age 6 months who were born prematurely. RSV is the most common cause of bronchiolitis and pneumonia in children under age 1. Bronchiolitis causes swelling and mucus production in the air passages in the lungs, which is particularly dangerous for infants whose small airways can easily become blocked as the infection progresses. Pneumonia causes inflammation of the lung tissue, which becomes filled with fluid.


Transmission
RSV spreads through close or direct contact with infected respiratory secretions, which may be coughed or sneezed into the air. The virus can survive for up to one hour on your hands and even longer on other surfaces. You can contract RSV by touching contaminated surfaces and then touching your eyes, mouth or nose, as well as simply inhaling infected respiratory droplets. The virus is easily inactivated by soap and water, as well as disinfectants.
The incubation period (time from exposure until symptoms appear) is two to eight days. Once symptoms appear, you're generally considered contagious for about three to eight days. However, infants may be contagious for up to four weeks. RSV can be contracted more than once, but repeat infections are usually not as severe.


Signs/symptoms
At first, an RSV infection may appear to be a simple cold marked by nasal congestion, a sore throat, low-grade fever and irritability. More serious symptoms may follow, including:
cough with thick sputum
thick nasal mucus
wheezing
difficulty breathing or rapid respiration
blue-tinged lips or nails
apnea (short episodes of stopped breathing)
difficulty eating
vomiting
Lethargy, irritability, difficulty eating and possibly apnea may be the only symptoms of RSV in infants, especially those born prematurely.


Diagnosis
Diagnosis is based on your current symptoms, a physical exam and lab tests. You may need blood tests, as well as studies of nasal or lung secretions. Sometimes, chest X-rays are also done.

Treatment
Depending on your overall health and the severity of the infection, your doctor may recommend getting plenty of rest and loosening lung and nasal secretions by using a humidifier and drinking more fluids. Saline nose drops can help as well. Sometimes, oxygen therapy may be needed. In other cases, bronchodilators (medications designed to open the airway) are prescribed. Antibiotics may be prescribed if you develop a secondary bacterial infection.
Although treatment can usually be done at home, hospitalization may be needed in severe cases. In the hospital, the antiviral medication ribavirin may be given to patients who are severely ill or considered to be at high risk for complications.


Complications
Premature infants, elderly adults, and adults and children who have severely weakened immune systems or heart or lung disease may become seriously ill when infected with RSV. Complications may include a secondary bacterial infection (often in the ear), pneumonia or lung or heart failure. For people who have asthma, RSV can make the condition worse. In extreme cases, RSV complications can be fatal.

Pregnancy-specific information
Pregnancy is not considered a risk factor for RSV.

Senior-specific information
Again, elderly adults have a higher risk of developing serious illness from RSV.

Prevention
To prevent infection, wash your hands often and avoid contact with anyone who's infected with RSV. It's best to avoid sharing eating utensils as well.
Development of an RSV vaccine is underway. In the meantime, various measures may be recommended to help prevent serious illness for certain high-risk children. For example:

The RSV immune globulin, which is given by intravenous infusion, may be recommended once a month during the RSV season. The first infusion should be done just before the season begins.

In other cases, the medication palivizumab (Synagis), which is given as an injection, may be recommended. Like the immune globulin, the shots would be repeated once a month during the RSV season.