May also be called: RSV

Respiratory syncytial (sin-sish-EE-ul) virus (RSV) is a contagious infection of the lungs and breathing passages.

More to Know

RSV is highly contagious and a major cause of respiratory illness in young children. The virus spreads through droplets in coughs or sneezes, or when someone touches a contaminated surface (like a countertop or doorknob).

Most children have had an RSV infection by age 2. Older kids might have only mild, cold-like symptoms (cough, stuffy nose, low-grade fever), but infants younger than 1 year old may have more severe symptoms and trouble breathing. Most at risk are premature babies and kids with diseases that affect the lungs, heart, or immune system.

RSV can cause respiratory illnesses, such as  croup, bronchiolitis, and pneumonia, as well as ear infections.

Home care and making kids as comfortable as possible usually is enough to manage RSV. Babies, though, might need to be hospitalized to watch for breathing difficulties and other problems.

Keep in Mind

Thorough and frequent hand washing is key in preventing the spread of RSV. At-risk infants can be given a monthly injection of a medication containing RSV antibodies during peak RSV season (roughly November to April).

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.