Respiratory Syncytial Virus IgM antibody Test

Human Respiratory Syncytial Virus is responsible for a majority of lower respiratory tract infections among infants between the ages of 6 months to 2 years and the elderly, with weakened immune systems. It is considered the most common cause for bronchiolitis and pneumonia in children below one year. Symptoms of RSV are mild, often indistinguishable from a common cold. But in some cases, RSV may cause severe bronchiolitis and require medical attention. There are multiple methods to detect RSV in the human body, like Rapid RSV antigen test, RSV RC-PTR molecular test or by using viral cultures. The most common Rapid RSV antigen is based on detection of antigens by secretion of IgM and IgA antibodies.

Since the test only requires a sample of your nasal wash, no dietary changes or a specific type of clothing is required.

If an RSV test is positive, then it is possible that the person has a respiratory syncytial virus infection. A positive test can also confirm the presence of RSV in the community. But the test is solely not sufficient to determine how severe the patient’s infection is likely to be or when exactly the patient was infected. Symptoms usually appear 4-6 days after infection.

Negative RSV tests may mean that the patient has no infection of RSV or that there is not sufficient virus in the sample to be detected. This may either be due to poor specimen collection or because the patient is not shedding detectable levels of virus into their nasal wash. Adults normally shed fewer viruses than infants do, and those who have had RSV for several days will shed less than those with a more recent infection.

The most frequently used sample to detect RSV is a nasal aspirate or wash. A syringe is used to push a small amount of sterile saline into the nose, then gentle suction is applied (for the aspirate) or the resulting fluid is collected into a cup. A variation of the procedure also uses nasopharyngeal, although it is not preferred because the amount of viruses obtained on a swab are usually low. The swab is collected by having the patient tip their head back, and a Dacron swab (looks like an ear swab) is gently inserted into one of the nostrils until resistance is met (about 1 to 2 inches in), then rotated several times and withdrawn. This is not painful, but it may tickle a bit and cause the patient’s eyes to tear.