Monospot test: definition, procedure, test results

Definition

What is a monospot?

The mononucleosis test is a blood test to look for antibodies that indicate mononucleosis (mono), which is usually caused by the Epstein-Barr virus (EBV). These antibodies are made by the immune system to fight infection.

The Monospot test (heterophil test) is a rapid scanning test to detect the type of antibody (heterophil antibody) that forms during a particular infection. The blood sample is placed on a microscope slide and mixed with another substance. If there are heterophil antibodies, the blood will clot. These results usually indicate mono infection. Monospot testing can usually detect antibodies 2-9 weeks after a person is infected. It is not usually used to diagnose mono that started more than 6 months earlier.

When should I have the monospot test?

A mono test is needed when a person, especially as a teenager or adult, is diagnosed with symptoms of mononucleosis by a doctor. Sometimes people confuse these symptoms with cold or flu symptoms. Some of the more common symptoms of mono include:

• fever
• headache
• sore throat
• swollen glands in the neck and / or armpits
• ongoing fatigue or tiredness

Some people may experience additional symptoms such as:

• stomach ache
• enlarged liver and / or spleen
• rash

The test can be repeated when the initial results show negative but the suspicion of mono remains high.

Precautions & warnings

What should I know before undergoing a monospot?

The mono test is quick and easy to perform, but specifically for heterophile antibodies, not EBV. This test also shows positive results in people with lymphoma, systemic lupus erythematosus (lupus), and some types of digestive cancer, although it is not used as a diagnostic or scanning tool for these conditions.

When the mono test is negative and / or the doctor wants more information about the presence and status of EBV infection, the doctor will order one or more of the EBV antibody combinations. This test can show whether a person is susceptible to EBV, has had a recent infection, has had an EBV infection in the past, or has an activated EBV infection.

Heterophilic antibodies decrease after the fourth week of illness, and the mono test will be negative because the infection has cleared up.

Process

What should I do before undergoing monospot?

No special preparation required. Discuss with your doctor any concerns you have about the need for the test, the risks, how it will be done, or what the results will mean.

What is the usual process for the monospot test?

A monospot test is done on a small sample of blood that is drawn from the tip of your finger or from a vein.

For finger samples, a healthcare professional will take samples by:

• clean your hands with soap and warm water or an alcohol swab
• massage your hands without touching the puncture area.
• prick the skin on the side of your middle or ring finger with a small instrument called a lancet
• wiped off the first drop of blood
• place a small tube called a capillary tube in the puncture area and collect a small amount of blood
• put gauze or cotton on the puncture area when the tube is removed
• put pressure on the area and then put a bandage on

What should I do after undergoing the monospot test?

You can remove the bandage and cotton for about 20 to 30 minutes. You will be given a date / time to get your test results. Your doctor will explain the test results that are meaningful to you. You must follow the instructions from your doctor.

Explanation of the Test Results

What do my test results mean?

Monospot test results are usually available within 1 hour.

Normal (negative): The blood sample does not form a clot (no heterophil antibodies are detected).

Abnormal (positive): There is a clot in the blood sample (heterophil antibody is detected). If there are clots in the blood sample, you may have mono.

Monospot in the second or third week of illness makes the diagnosis of infectious mononucleosis very unlikely, but during the first week of illness, the test may show a false negative result. If necessary, further testing for specific antibodies to Epstein-Barr virus (EBV serology) may be performed. The serologic components of EBV include EBV IgM (usually indicating recent infection) and EBV IgG (usually indicating previous infection).