RSV Test

An RSV test detects the respiratory syncytial virus in respiratory samples (usually a nasal or nasopharyngeal swab). Available as rapid antigen tests (results in 15–30 minutes) or more sensitive PCR tests (hours to days). Testing confirms infection in infants, older adults, or high‑risk patients to guide treatment, infection control, and sometimes hospital care. Clinicians choose tests based on accuracy and turnaround time.

You can sometimes test for RSV at home using specific rapid antigen nasal‑swab kits available in some regions, but not all home tests include RSV. At‑home kits are less sensitive than laboratory PCR; false negatives can occur, especially early in illness. If you’re high‑risk, have severe symptoms, or a home test is negative despite symptoms, seek clinical testing and medical advice for accurate diagnosis and care.

RSV positive means respiratory syncytial virus is present. RSV is caused by infection with the RSV virus, transmitted via respiratory droplets, direct contact with infected secretions, or contaminated surfaces. It commonly infects the nose, throat and lower airways, causing cold-like symptoms, bronchiolitis or pneumonia, especially in infants, older adults, and people with weakened immune systems.

RSV is confirmed mainly by detecting the virus in respiratory specimens. The most accurate test is PCR on nasopharyngeal or nasal swabs; rapid antigen tests offer quicker but less sensitive results. Viral culture is rarely used. Clinicians may rely on clinical signs during RSV season, but laboratory testing is recommended for infants, elderly, immunocompromised, or severe respiratory illness to guide care and infection control.

RSV is usually detectable by rapid antigen tests for about 3–7 days after symptoms start. PCR (molecular) tests are more sensitive and can remain positive for 1–3 weeks; infants and immunocompromised people may shed virus and test positive for several additional weeks. Test positivity doesn’t always mean infectiousness, so follow clinical advice on isolation and care.

Accuracy depends on test type and timing. Rapid antigen tests have moderate sensitivity (about 50–80%), so they miss some infections, especially in adults or later in illness; specificity is generally high. Molecular PCR tests are much more accurate (sensitivities and specificities typically above 95%), making them the preferred diagnostic method. Sample quality and timing (early in infection) significantly affect results; false negatives can still occur.