Respiratory syncytial virus (RSV) is a common respiratory virus that infects the nose, throat, lungs, and breathing passages. RSV spreads through contact with respiratory droplets (coughing, sneezing, or kissing) from an infected person or touching surfaces contaminated with the virus and then touching your eyes, nose, or mouth. RSV can survive for many hours on hard surfaces such as tables and crib rails. The virus typically lives on soft surfaces such as tissues and hands for shorter amounts of time. Children are often exposed to RSV outside the home, in school or daycare centers. They can then transmit the virus to other members of the family.

RSV is so widespread that almost all children will have had an RSV infection by their 2nd birthday. Even though RSV is often associated with mild, cold-like symptoms, it can be serious and can lead to severe illness. While certain groups including premature and very young infants (≤6 months), individuals with chronic heart or lung disease, immunocompromised individuals, and older adults (65+), are at increased risk for severe disease, the potential for dangerous complications is a concern for all age groups.

Burden
In the US, RSV is the most common cause of bronchiolitis (inflammation of the small airways in the lung) and pneumonia in children <1 year, and leads to approximately 1.5 million outpatient visits, 520,000 emergency department visits, 58,000 hospitalizations, and an estimated 100 to 500 deaths among children younger than age five years annually. The virus is also increasingly recognized as a significant cause of respiratory illness in older adults in the US and is estimated to cause 177,000 hospitalizations, and 14,000 deaths in adults age 65 years and older annually. The actual burden among all age groups is likely even higher due to underreporting of RSV infections.

Individuals of all ages can get an RSV infection but those at highest risk for severe disease include:

premature infants and infants age 6 months and younger
individuals with chronic heart or lung disease
individuals with compromised immune systems
older adults (65+).

Like other respiratory viruses like influenza (flu) or COVID-19, symptoms of RSV infection usually include runny nose, coughing, sneezing, fever, decreased appetite, and wheezing. The symptoms usually appear in stages. In very young infants, the only symptoms may be irritability, decreased activity, and breathing difficulties. Those infected with RSV usually show symptoms within 4 to 6 days after getting infected. Healthy adults infected with RSV may have few symptoms but can still spread virus to others.

Individuals infected with RSV are usually contagious for 3 to 8 days and recovery usually takes 1 to 2 weeks. However, some infants, and those with weakened immune systems, can continue to spread the virus even after they stop showing symptoms, for as long as 4 weeks.

RSV typically circulates with other seasonal respiratory viruses, like flu. However, the COVID-19 pandemic has impacted normal transmission patterns of RSV, leading recently to more unusual, “out of season” exposures and infections. Given its similarities in symptoms and co-circulation with other viral infections, the only way to determine if someone has an RSV infection is through clinical laboratory testing.

The best ways to help prevent the spread of RSV include the following:

• Cover coughs and sneezes
• Wash hands often with soap and water for at least 20 seconds
• Avoid close contact, such as kissing, shaking hands, and sharing cups and utensils, with others
• Avoid touching the face
• Clean frequently touched surfaces (such as doorknobs)
• Consult a healthcare professional if you have cold-like symptoms that linger or worsen.
• Researchers are currently working to develop new tools to prevent RSV including vaccines and monoclonal antibodies targeted for specific populations, including infants/young children, older adults, pregnant mothers, and adults with compromised immune systems.

An antiviral drug called palivizumab (pah-lih-VIH-zu-mahb) is available to prevent severe RSV illness in high-risk infants (born prematurely or with congenital heart disease or chronic lung disease). However, the use of palivizumab is limited as it can only be used in certain children considered at high risk for complications, does not help cure or treat children already suffering from serious RSV disease, and cannot prevent RSV infection.Updated February 2022