In otherwise healthy people, it is not usually necessary to distinguish respiratory syncytial virus (RSV) infection from a common cold. A health professional may suspect RSV infection as the cause of symptoms when there is evidence of a recent community outbreak. It is generally not necessary to confirm RSV infection with lab tests. However, a medical history and physical exam may be done to evaluate symptoms.

A viral detection test may be done to confirm a diagnosis of RSV in symptomatic children and adults older than 65 who are at an increased risk for a severe infection or for complications. This test involves lab analysis of nasal drainage, obtained with a cotton swab or nasal wash. Testing may also be recommended for people who are hospitalized if the cause of symptoms has not already been determined and they have a high risk of developing complications.

The results of viral detection tests help determine whether precautions are needed to prevent the spread of infection. For children who have a risk of getting severe infections or complications of RSV infections, the results of these tests may help guide treatment, such as the need for medicines.

Certain tests may be needed if RSV symptoms do not improve or become worse or if complications, such as bronchiolitis or pneumonia, are suspected. These tests may include:

• A chest X-ray, which may show signs of pneumonia.
• Blood tests, such as a chemistry screening, a complete blood count, or arterial blood gases (ABGs) analysis.
• Oximetry, to measure the amount of oxygen in the blood.