Rapid Detection of Respiratory Syncytial Virus
Does this test have other names?
RSV rapid detection, RSV indirect immunofluorescence assay, IFA
What is this test?
This test looks at cells taken from fluid in your nose or throat to see if you have respiratory syncytial virus (RSV). RSV attacks the upper respiratory tract.
This test looks for antigens in these nose or throat cells to quickly diagnose an infection. An antigen is a substance in the virus that causes your body's immune system to make antibodies. The test is accurate 80 to 90 percent of the time.
If you have RSV, you can spread it to others through coughing and sneezing for about 10 days after your symptoms start. Once you have been infected, you are less likely get it again. If you do, your symptoms are likely to be milder.
If your symptoms are severe, you may be treated with a medication called ribavirin.
Why do I need this test?
You may need this blood test if you have symptoms of RSV and you are at risk for a serious infection. Symptoms of RSV infection may include:
For most people, RSV symptoms go away on their own within a few days to a few weeks. But babies, young children, older adults, and people with weak immune systems are at risk for severe infections from this virus.
Your doctor may order this test to:
Make an early and quick diagnosis to start early treatment
Make an early and quick diagnosis to help prevent you from spreading the virus to others
Diagnose RSV so that your doctor can rule out other causes of respiratory disease
What other tests might I have along with this test?
Your doctor may also use a cell culture to test your nasal or throat secretions. Blood tests to diagnose RSV are also available, but it takes a long time to get the results.
What do my test results mean?
Many things may affect your lab test results. These include the method each lab uses to do the test. Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your health care provider.
Normal results are negative, meaning you don't have RSV. If your test is positive, you may be infected with RSV.
How is this test done?
This test requires a sample of secretions from the area at the back of your nose and throat. Your doctor may collect the sample by using a swab, a soft rubber bulb, or a plastic tube called a catheter. You may need to tip your head back for this.
Does this test pose any risks?
This test poses no known risks. You may feel some mild discomfort or a gagging sensation.
What might affect my test results?
This test may be affected by how soon the test is done after your infection starts. It works best if the test is done in the first four days after symptoms begin. The results are more reliable in young children and less reliable in older children and adults.
How do I get ready for this test?
You don't need to prepare for this test. But be sure your doctor knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use.
- Bass, Pat F. III, MD, MPH
- Fraser, Marianne, MSN, RN