Respiratory syntactical (sin-SIS-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.

RSV Symptoms

Symptoms of RSV infection usually include

• Runny nose
• Decrease in appetite
• Coughing
• Sneezing
• Fever
• Wheezing

These symptoms usually appear in stages and not all at once. In very young infants with RSV, the only symptoms may be irritability, decreased activity, and breathing difficulties.

RSV can also cause more severe infections such as bronchiolitis, an inflammation of the small airways in the lung, and pneumonia, an infection of the lungs. It is the most common cause of bronchiolitis and pneumonia in children younger than 1 year of age.

Almost all children will have had an RSV infection by their second birthday. People infected with RSV usually show symptoms within 4 to 6 days after getting infected.

RSV Care

Most RSV infections go away on their own in a week or two. You can manage fever and pain with over-the-counter fever reducers and pain relievers, such as acetaminophen or ibuprofen. Talk to your healthcare provider before giving your child nonprescription cold medicines, since some medicines contain ingredients that are not recommended for children. It is important for people with RSV infection to drink enough fluids to prevent dehydration (loss of body fluids).

Healthy infants and adults infected with RSV do not usually need to be hospitalized. But some people with RSV infection, especially infants younger than 6 months of age and older adults, may need to be hospitalized if they are having trouble breathing or are dehydrated. In most of these cases, hospitalization only lasts a few days.

Visits to a healthcare provider for an RSV infection are very common. During such visits, the healthcare provider will evaluate how severe the person’s RSV infection is to determine if the patient should be hospitalized. In the most severe cases, a person may require additional oxygen or incubation (have a breathing tube inserted through the mouth and down to the airway) with mechanical ventilation (a machine to help a person breathe).

There is no specific treatment for RSV infection, though researchers are working to develop vaccines and antivirals (medicines that fight viruses).

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 Symptoms

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 syncytial 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

RSV Diagnosis

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