Respiratory Syncytial Virus (RSV)
What is RSV?
RSV is a virus that is a major cause of respiratory illness in young children, causing infection of lungs and breathing passages. In adults and children over age 3, its symptoms resemble the “common cold,” but in children under age 3, RSV can cause serious illnesses like bronchitis and pneumonia.
RSV attacks the mucous membranes of the respiratory tracts (nose, windpipe and air passages of the lungs). “Syncytial” means that the virus causes cells of the mucus membranes to merge together into larger cells. Because infants and their air passages are small, an RSV infection can clog up their air passages much more easily. Symptoms resemble those of a common cold, but can also result in wheezing and pneumonia.
How does RSV spread?
RSV is very contagious. The infection is often carried home by a school-aged child and passed on to a younger sibling, especially an infant. When RSV infects a day care center, it typically infects all the children.
The highest rates of RSV illness occur in infants two to six months old, peaking at the age of two to three months.
In children under nine months old, RSV bronchiolitis can be life-threatening.
How long can RSV last?
The wheezing and tight breathing worsen two or three days after symptoms begin, and then improve slowly. Overall, the wheezing lasts about seven days and the cough about two weeks.
RSV infections generally last for one to two weeks, but some cases may have symptoms lasting up to three weeks. Children who are hospitalized with lower respiratory tract illness usually spend five to seven days there, where they may receive supplemental oxygen, humidified air and hydration with intravenous fluids. The most common complication of bronchiolitis is an ear infection, which occurs in about 20% of infants. Bacterial pneumonia occurs less often.
After each RSV infection, the body develops some immunity to the virus, but it is never complete or permanent. Re-infections occur, but are usually less severe than earlier RSV attacks.
What are the symptoms of RSV?
- High fever
- Severe, frequent cough (often described as a “seal bark” cough)
- Runny nose and nasal congestion
- Nasal flaring and shortness of breath
- Wheezing
- Abnormally rapid breathing or difficulty breathing
Symptoms generally begin gradually over four to six days after exposure. Someone with an RSV infection, even if it’s “just a cold,” can pass infectious RSV particles through oral and nasal fluids. Contagiousness peaks during the first two to four days of illness, but RSV particles may still be spread for up to two weeks after the stuffy nose begins.
A young child with RSV may be infectious for one to three weeks after symptoms subside. Transmission occurs by touching an infected person and then rubbing your own eyes, nose or mouth. RSV can survive for eight hours on surfaces such as cribs, countertops and toys.
How is RSV diagnosed?
Chest x-rays are used to detect pneumonia or bronchiolitis. A sample of nasal secretions is taken to use in a lab test to determine if RSV is present. An arterial blood gas analysis shows the level of oxygen saturation in the blood.
What treatment is available?
Mild infections can resolve without treatment. Severe infections in infants and children may require hospitalization. RSV infections are not treated with antibiotics because they do not work against viruses.
Infants born prematurely or who have had chronic lung disease are considered at high risk for severe illness if they are infected with RSV. These infants can get a monthly vaccine called Synagist to help protect them from RSV infection.
Contact your physician immediately if you notice:
- Difficulty breathing or very rapid breathing
- Skin between ribs pulls in while child struggles to catch his or her breath
- Bluish or gray color appears on lips, skin or fingernails
- Child appears less alert than usual, or unusually irritable or inactive
- Child refuses to drink
- Fever of more than 102 degrees F (38.3 degrees C)
Call for an appointment if:
- Cough frequency increases or child is not resting well because of cough
- Thick nasal discharge is yellow, green or gray
