What Is the RSV Test?
The respiratory syncytial virus (RSV) antibody test is a blood
test used to diagnose a respiratory syncytial virus (RSV) infection. The test
detects the presence of antibodies to the RSV pathogen. Antibodies are proteins
that your body’s immune system releases naturally in response to a harmful
substance, called an antigen.
Specifically, the RSV test detects the presence of antibodies
that your body has produced to fight the RSV virus. The test can be used to
diagnose either a recent or a past RSV infection.
RSV is a major cause of human respiratory infections, particularly
among the younger populations. The
infection is most severe and occurs most frequently in young children. In
infants, the virus can cause bronchiolitis (inflammation of the airways in
their lungs), pneumonia (inflammation of their lungs) or croup (swelling in their
throat that leads to breathing difficulties and a cough). In older children,
adolescents, and adults, infection with RSV tends to be less severe.
The infection is seasonal — usually occurring in late fall to
spring (peaking in the cold winter months) — and it commonly occurs as an
epidemic. This means that it affects a large number of individuals within a
community at the same time. The Centers
for Disease Control and Prevention (CDC) report that nearly all children
will be infected with RSV by the time they turn 2 years old, but only a small
percentage will experience severe symptoms.
When Is the RSV Test Used?
Symptoms of an RSV infection are similar to those of other types
of respiratory infections. They may include:
- runny nose
- decreased appetite
The test is often performed on premature infants or children
under the age of 2 who have congenital heart or chronic lung disease or a
weakened immune system. According to the CDC, infants and
children with these conditions are at highest risk of severe infections,
including pneumonia and bronchiolitis.
How Should You Prepare for the Test?
No special preparation is required for this test.
Be sure to tell your doctor about any medications — prescription
or otherwise — you currently take, because they may affect the results of this
How Is the Test Performed?
The RSV antibody test is a blood test performed by a nurse at
your doctor’s office. Blood will be drawn from a vein, usually at the inside of
your elbow. A blood draw typically involves the following steps:
- The puncture site is cleaned with an antiseptic.
- A healthcare provider (often your doctor or a
nurse) wraps an elastic band around your upper arm in order to make your vein
swell with blood.
- A needle is gently inserted into your vein to
collect blood in an attached vial or tube.
- The elastic band is removed from your arm.
- The blood sample is sent to a laboratory for
What Are the Risks of Taking the Test?
As with any blood test, there’s a slight risk of bleeding,
bruising, or infection at the puncture site. You may feel moderate pain or a
sharp prick when the needle is inserted. You may also feel dizzy or lightheaded
after the blood draw.
What Do the Results Mean?
A normal, or negative, test result indicates that there are no
antibodies for RSV in your blood. This means that you’ve never been infected
In infants, a positive test result may indicate that the baby has
had an RSV infection (recently or in the past), or their mother has passed RSV
antibodies to them in utero (before birth). In adults, a positive result means they
have had an RSV infection recently or in the past.
Your doctor can use the results of your test to distinguish
between a recent and a past infection. In general, the presence of IgM
antibodies indicates recent infection, and the presence of IgG antibodies
indicates past infection. Most adults and older children have already had an
RSV infection and already have RSV antibodies.
What Happens If the Results Are Abnormal?
In infants with symptoms of an RSV infection and positive test
results, hospitalization is typically not required because symptoms usually
resolve at home in one to two weeks. The CDC states that most
children who need to be hospitalized for RSV infection are younger than 6
months of age. There’s no specific treatment available for RSV infection and,
at present, no RSV vaccine has been developed.