At a glance
Why get tested?
To determine whether an infant, an elderly person, or an person has respiratory syncytial virus (RSV). Also, to help determine whether or not RSV season has started and to track its progess in the community
When to get tested?
When it is RSV season (late autumn through early spring) and your doctor wants to determine whether your runny nose, congestion, coughing and/or difficulty breathing are due to RSV or to other causes
Usually a nasal or nasal wash; occasionally a nasopharyngeal (NP) swab
Test preparation needed?
What is being tested?
RSV testing is used to detect respiratory syncytial virus, the most common cause of lower respiratory tract infections in infants around the world. RSV tends to be seasonal, causing community in young children, older adults, people and those with pre-existing lung disease. Typically the season begins in late autumn and disappears in early spring. Affected people may have symptoms such as severe coughing, wheezing, difficulty breathing and high fevers. For many, symptoms may be no worse than a common cold, but RSV can be life-threatining for the very young, the immunocompromised, those with pre-existing lung disease or the elderly.
RSV testing detects virus that is being shed in the respiratory/nasal secretions of someone who is infected. Since detectable amounts of virus are usually only shed for the first few days of an infection, most testing must be done during this time period. There are several methods to test for the virus, including rapid RSV testing, detection of RSV nucleic acids by , immunofluorescent antibody (IFA) tests and viral culture. Rapid RSV antigen tests are often performed in the doctor’s office or the emergency room, with most results available within an hour. However, rapid antigen testing lacks sensitivity unless performed in a situation where the likelihood of infection is already high (for example, testing an infant with typical symptoms during an epidemic). In other situations, the sample may be collected and sent to a laboratory for a more and testing method such as PCR or IFA tests. In many laboratories the test for RSV is combined with tests for multiple respiratory viruses. Results of these RSV tests are usually available the same day.
Viral (to grow the RSV virus) is not routinely performed by laboratories. This is because RSV is difficult and slow to culture.
How is the sample collected for testing?
Sample collection technique is critical in RSV testing. The best and most commonly used sample is a nasal or wash. A syringe is used to push a small amount of sterile saline into your nose, then gentle suction is applied (for the aspirate) or the resulting fluid is collected into a cup (for a wash).
Sometimes, a nasopharyngeal (NP) swab is used, although it is not preferred because it collects a smaller amount of the virus in the sample. The NP swab is collected by having you tip your head back, then a Dacron swab (like a long Q-tip) is gently inserted into one of your nostrils until resistance is met (about three to six centimetres in) then rotated several times and withdrawn. This is not painful but it may tickle a bit and cause your eyes to water.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.