RSV Tests: Rapid Antigen Tests and rRT-PCR

Medically Reviewed by Neha Pathak, MD on May 15, 2024
8 min read

RSV is short for respiratory syncytial virus. It’s a virus that can cause respiratory infections in your lungs, nose, and throat. 

RSV spreads easily from one person to the next. Usually RSV symptoms look a lot like the common cold or other respiratory infections. You may have a runny or stuffy nose, cough, fever, sore throat, sneezing, or a headache. 

Since these symptoms don’t look much different from many other infections such as COVID-19 or the flu, you might want to take an RSV test to find out if that’s what you have. An RSV test will look for the virus in a sample usually from your nose or mouth. 

Most of the time, you won’t need to test to see if your symptoms are caused by RSV. The reason is that it won’t usually change your treatment. Most people get better at home. But you might want an RSV test, especially if your symptoms are more severe or you are at more risk for breathing problems from RSV due to your age or other health conditions. 

How to test for RSV in adults vs. infants

RSV tests usually are run on samples from your nose. A doctor may put saline (salt water) in your nose and then collect it. Or they may use a swab to take a sample. 

In infants, doctors might swab the mouth instead. Or they may look at a blood test. If a baby is very sick or having trouble with breathing, a doctor might order other tests, including imaging tests, blood, or urine tests.

It’s best to test for RSV soon after your symptoms start. That’s because you’ll likely have the most virus in your system then. As you get better, the amount of virus will go down.

Where can I get an RSV test?

Your doctor may order an RSV test for you. You can also get tested at a drugstore clinic or urgent care. Ask your doctor what they’d recommend. You may not need an RSV test since most people get better at home without treatment.

Your doctor can order different types of tests that look at different things. Ask your doctor about differences among tests in accuracy and how long it will take to get your results.

RSV rapid tests

This is the most likely way you’ll be tested for RSV. The test looks for certain proteins, or antigens, from RSV in a sample from your nose. Rapid tests usually give results within an hour.

Molecular test for RSV

Another name for a molecular test is rRT-PCR. It stands for real-time reverse transcriptase-polymerase chain reaction. These tests look at genetic material instead of proteins. The tests are more sensitive than antigen tests, which means they can find the virus when it’s present in smaller amounts. 

This type of test can look for more than one type of infection at the same time. Your sample will probably get sent to a lab, and it will take longer to get your results.

RSV antibody test

Another type of RSV test looks for antibodies in your blood that your body makes after you’ve had an RSV infection. This type of test requires a blood sample. It can’t tell you if you have RSV right now. Instead, it can tell you if you’ve had RSV recently or in the past. 

You probably won’t have this type of test unless you’re involved in a research or monitoring study. Sometimes public health officials will use this type of test to measure an RSV outbreak.

Viral culture

This type of test isn’t usually done. It involves adding a sample to cells in the lab to see if the virus multiplies and infects the cells. 

At-home RSV test kits

Another way to test for RSV is to collect your own sample at home using an at-home collection kit. You can order an at-home test online. You’ll need to send your sample off to a lab where they’ll run the test. Once the results are back, you’ll log in online to get them.

Combination COVID-19 + flu + RSV at-home test

The FDA has approved an at-home test to look for COVID-19, flu, and RSV in one test. You don’t need a prescription from your doctor to get it. It’s the first test that checks for RSV, influenza A and B, and COVID-19 in one sample taken from your nose.

How to take an at-home COVID-19 + flu + RSV at-home test 

You should always read the directions carefully when taking any at-home test before you collect your sample. Parents should get the sample for kids between ages 2 and 13. It’s a good idea to help older teens, too, to make sure they get the sample the right way.

You’ll need to send the sample the same day you collect it. Make sure you collect it at a time during the week when you know it will go out.

Make sure to wash your hands and keep all items in the kit clean. You’ll swab your nose or your child’s nose as directed and then place it in a tube. Once you seal it up, put it in the specimen bag and get it ready to ship. 

Your test results will be either positive or negative. A negative test means no RSV was detected in your sample. A positive test means RSV was detected in your sample.

If your test is negative, it doesn’t mean you definitely don’t have RSV. You may not have gotten a good sample or the amount of virus in your sample may not have been enough to get a positive test result. 

How accurate is an RSV test?

It depends what type of test you got. A rapid antigen test detects proteins called antigens in your sample. These tests will give you an accurate result up to 90% of the time.

RT-PCR tests are more sensitive and accurate than a rapid antigen test. But the accuracy of your results will depend on your sample. One study found that collecting more than just a nasal swab could make an RT-PCR test better able to spot RSV. 

RSV tests are generally better at finding the virus in infants and young children who haven’t had RSV before. That’s because they’ll have more virus in their systems. By comparison, rapid antigen tests for older kids, teens, and adults will more often miss an RSV infection due to lower viral loads.

Healthy older kids and adults usually don’t need a test for RSV. But if you want to run an RSV test, it’s best to use a more sensitive RT-PCR test, which will give you a more accurate result.

RSV testing doesn’t come with much risk since you will usually just get a sample from your nose. You may find it a little uncomfortable to get the sample. But any effects should be minor and temporary. 

If you’re healthy, you probably don’t need a test to find out if you’ve got RSV. Your doctor might recommend it for:

  • Infants

  • Young children

  • Adults over 65

  • People with a weak immune system

  • People who have a heart or lung disease

But it’s more likely if your symptoms are moderate to severe. You may need an RSV test if you have symptoms including:

  • Fever

  • Wheezing

  • Bad cough

  • Fast, abnormal, or troubled breathing

  • Blue skin

Symptoms of RSV in young infants include:

  • Being unusually cranky

  • Moving less than normal

  • Not eating

  • Pauses between breaths

Most people with RSV will get better within a couple of weeks. If you have an RSV infection that’s severe or life-threatening, you may need to stay in the hospital. That happens most often in premature infants or people with chronic heart or lung disease.

If you’re worried about getting an RSV infection, a vaccine is recommended for older adults and pregnant women. An antibody that can help prevent severe RSV infection is also available for infants and young kids. Ask your doctor what they recommend to help you avoid RSV.

When to see your doctor

Most people who get a positive RSV test will get better without treatment. But some people can get more severely ill. RSV is a common cause of bronchiolitis and pneumonia in kids under 1. See a doctor if you or your child is:

  • Struggling to breathe

  • Dehydrated

  • Not getting better or having symptoms that are getting worse

When RSV is severe, you or your child may need:

  • Oxygen

  • IV fluids

  • Mechanical ventilation 

Most people who are admitted to the hospital with RSV go home within a few days.

Most people don’t need a test to tell them whether their cold-like symptoms are caused by RSV. But you may want to get tested if you’re in a high-risk group or if your very young child has symptoms that may be RSV. Ask your doctor what kind of test they recommend for you or your child and why.

What are the tests for RSV?

You can get different types of tests for RSV. Most will look for RSV proteins or genetic material in a sample from your nose. A rapid antigen test will get you an answer fastest, but they aren’t as sensitive as rRT-PCR tests that look at genetic material.

How do I know if I have RSV?

The only way to know for sure that your symptoms are caused by RSV is to get a test. Sometimes a test may give you a false negative if you don’t take it at the right time or you don’t have enough virus in your sample.

What is the protocol for RSV testing?

You don’t need any special preparation to get an RSV test. You’ll likely get a nasal swab. Some tests will require your sample to be sent off to a lab for testing.

Is there a quick test for RSV?

Yes. A rapid antigen test to look for RSV proteins can give you a result in under an hour. Other, more sensitive tests look at genetic material and will take longer. At-home tests are quick to do, but you’ll have to send your sample to a lab for testing.

How do I tell if I have RSV or a cold?

The symptoms of RSV and a cold often look similar. The only way to know for sure what type of respiratory virus you have is through testing. For most people, test results won’t change your treatment, so testing isn’t usually recommended for healthy older kids and adults. If you’re worried an infant may have RSV or an older person with other risk factors, see a doctor and ask about an RSV test.