Respiratory syncytial virus

Respiratory syncytial virus (RSV), an RNA virus, infects cells lining the airways and causes infections that range from the nose down to the lungs. Infection is extremely common in small children, with nearly all infected by the age of two, and it also affects older adults. It spreads through coughs and sneezes, direct contact and contaminated surfaces; severe illness is likelier in young infants, premature babies, older adults and people with weakened immunity or chronic heart or lung disease. Most people have cold-like symptoms such as a runny nose, cough, sneezing and fever, while severe cases bring bronchiolitis or pneumonia with wheezing and fast breathing. Diagnosis rests on history and examination, with laboratory testing of nasal fluid or other respiratory samples usually kept for severe infection. No specific treatment exists; care is supportive, with fluids and oxygen for severe cases, and vaccines and monoclonal antibody injections are used for prevention.

Seek urgent care for a high fever with a stiff neck, rash, confusion, difficulty breathing, or fever after travel to a malaria area. See a doctor when a fever lasts more than three days, when symptoms return after treatment, or when you may have been exposed to an infection that needs testing. Call the local emergency number for any symptom that is sudden and severe. This page is a reference for healthcare professionals and does not replace an assessment.