Respiratory syntactical (sin-HISS-uhf) virus, or RSV, is a common respiratory virus that usually causes mild, cold-like symptoms. Most people recover in a week or two, but RSV can be serious, especially for infants and older adults. In fact, RSV is the most common cause of bronchiolitis (inflammation of the small airways in the lung) and pneumonia (infection of the lungs) in children younger than 1 year of age in the United States. It is also a significant cause of respiratory illness in older adults.
Respiratory syntactical virus (RSV) is a very common virus that leads to mild, cold-like symptoms in adults and older healthy children. It can be more serious in young babies, especially those in certain high-risk groups.
RSV is the most common germ that causes lung and airway infections in infants and young children. Most infants have had this infection by age 2. Outbreaks of RSV infections most often begin in the fall and run into the spring.
The infection can occur in people of all ages. The virus spreads through tiny droplets that go into the air when a sick person blows their nose, coughs, or sneezes.
You can catch RSV if:
- A person with RSV sneezes, coughs, or blows their nose near you.
- You touch, kiss, or shake hands with someone who is infected by the virus.
- You touch your nose, eyes, or mouth after you have touched something contaminated by the virus, such as a toy or doorknob.
RSV often spreads quickly in crowded households and day care centers. The virus can live for a half an hour or more on hands. The virus can also live for up to 5 hours on countertops and for several hours on used tissues.
The following increase the risk for RSV:
- Attending day care
- Being near tobacco smoke
- Having school-aged brothers or sisters
- Living in crowded conditions
Respiratory syntactical virus (RSV) 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 syntactical (sin-DISH-ul) virus can also infect adults.
In adults and older, healthy children, RSV symptoms are mild and typically mimic the common cold. Self-care measures are usually all that’s needed to relieve any discomfort.
RSV can cause severe infection in some people, especially premature babies, older adults, infants and adults with heart and lung disease, or anyone with a very weak immune system (immunocompromised).
Signs and symptoms of respiratory syntactical virus infection most commonly appear about four to six days after exposure to the virus. In adults and older children, RSV usually causes mild cold-like signs and symptoms. These include:
- Congested or runny nose
- Dry cough
- Low-grade fever
- Sore throat
- Mild headache
In severe cases
Respiratory syntactical virus infection can spread to the lower respiratory tract, causing pneumonia or bronchiolitis — inflammation of the small airway passages entering the lungs. Signs and symptoms may include:
- Severe cough
- Wheezing — a high-pitched noise that’s usually heard on breathing out (exhaling)
- Rapid breathing or difficulty breathing — the child may prefer to sit up rather than lie down
- Bluish color of the skin due to lack of oxygen (hypnosis)
Infants are most severely affected by RSV. You may notice your child’s chest muscles and skin pull inward with each breath. This is a sign that he or she is struggling to breathe. Other signs and symptoms of severe RSV infection in infants include:
- Short, shallow and rapid breathing
- Poor feeding
- Unusual tiredness (lethargy)
Most children and adults recover in one to two weeks, although some might have repeated wheezing. Severe or life-threatening infection requiring a hospital stay may occur in premature babies or infants and adults who have chronic heart or lung problems.
When to see a doctor
Seek immediate medical attention if your child — or anyone at risk of severe RSV infection — has difficulty breathing, a high fever, or a blue color to the skin, particularly on the lips and in the nail beds.
Respiratory syntactical virus (RSV) is a common, and very contagious, virus that infects the respiratory tract of most children before their second birthday.
For most babies and young children, the infection causes nothing more than a cold. But for a small percentage, infection with RSV can lead to serious, sometimes life-threatening problems such as pneumonia or bronchiolitis, an inflammation of the small airways of the lungs.
RSV infection can cause cold-like symptoms, including a cough and runny nose, which usually last 1 to 2 weeks.
When to see a doctor: Call your baby’s doctor if you notice any of the following RSV symptoms:
- A high-pitched whistling or wheezing noise when they breathe
- Being unusually upset or inactive
- A cough with yellow, green, or gray mucus
- Trouble breathing or pauses in their breaths
- Refusing to breastfeed or bottle-feed
- Signs of dehydration: lack of tears when crying, little or no urine in their diaper for 6 hours, and cool, dry skin
If your baby is very tired, breathes rapidly, or has a blue tint to their lips or fingernails, call 911 or go to the ER immediately.
RSV Causes and Risk Factors
Respiratory syntactical virus spreads through the air, like after a cough or a sneeze, and through direct contact like touching.
The chance of a severe infection is highest for:
- Babies born prematurely
- Children younger than 2 who were born with heart or lung disease
- Infants and young children whose immune systems are weakened because of illness or medical treatment
- Children under 8 to 10 weeks old
To diagnose RSV, your child’s doctor will probably look at their medical history and do a physical exam, including listening to their lungs.
Your doctor might do some tests if your child is very sick or in order to rule out other problems. Tests for RSV include:
- Blood and urine tests to look for a bacterial infection and make sure your child isn’t dehydrated
- Chest X-rays to look for any signs of pneumonia
- Tests of material scraped out of your child’s nose or mouth