To get screened for infectious mononucleosis (glandular fever).
A blood sample taken from a vein in your arm
The Monospot test detects heterophil antibodies. It detects a reaction with horse red blood cells. A similar test, the Paul-Bunnell test, detects a reaction with sheep red blood cells. The antibodies are made in response to an infection by Epstein-Barr virus (EBV). EBV causes infectious mononucleosis (glandular fever), a self-limiting disease.
Mononucleosis is characterised by the presence of atypical white blood cells (atypical lymphocytes) in an infected person. Patients have these symptoms: fever, sore throat, swollen glands, and fatigue. About 70%–80% of patients with infectious mononucleosis produce these heterophil antibodies, which are not specific for EBV infection but are a good predictor of EBV infection.
How is the sample collected for testing?
A blood sample is taken by needle from a vein in the arm.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.
How is it used?
When is it requested?
The Monospot test is requested if your doctor suspects that you have infectious mononucleosis, which causes fever, headache, swollen glands, tiredness, and malaise. Your healthcare professional may detect that you have an enlarged spleen or liver.
The test will not be positive until you have been infected for about two weeks. Other tests may need to be requested if the heterophil antibodies are negative, but your doctor still suspects mononucleosis as the cause of your symptoms.
Other blood tests that are more specific to the EBV can be used to find early infection or to confirm mononucleosis. These tests include the IgM and IgG antibodies to the viral capsid antigen (VCA), which can be found early in the disease. VCA IgM is only present in the few weeks after infection, but the IgG antibodies can also be found later, during the patient's recovery. Antibodies to Epstein-Barr virus Nuclear Antigen (EBNA) may also be tested for to gain a more accurate indication of recent or previous EBV infection.
What does the test result mean?
A positive result in the Monospot test, together with symptoms of mononucleosis, are the basis for a diagnosis of infectious mononucleosis. In addition to a positive reaction on the Monospot test, an infected person has a higher white blood cell count, with a higher than usual number of atypical lymphocytes. Heterophil antibodies decline after the fourth week of illness, and the Monospot test will become negative as the infection resolves.
A negative test result means that a person may not have mononucleosis or that it is too early in the illness to detect the antibodies. The test may need to be repeated if symptoms remain. Infants and young children do not make heterophil antibodies when infected with EBV, so more specific viral tests must be used to make the diagnosis.
Interpretation of Specific EBV Test results
EBV IgM antibody EBV IgG antibody EBNA antibody Interpretation Positive Negative Negative Recent EBV infection Positive Positive Negative Recent EBV infection Negative Positive Positive Previous EBV infection
Is there anything else I should know?
In young adults, an effective laboratory diagnosis can be made on a single blood sample during the acute phase of the disease with a Monospot test. By requesting the more extensive battery of EBV blood tests, the healthcare professional will be able to learn whether a person is susceptible to EBV, has had a recent infection, has had EBV infection in the past, or has a reactivated EBV infection.
When the Monospot test is negative, a combination of EBV antibody tests for IgM and IgG to the viral capsid antigen, IgM to the early antigen, and IgG antibody to the nuclear antigen may be requested, as well as antibody tests for cytomegalovirus (CMV) or Toxoplasma gondii.
How serious is infectious mononucleosis?
The symptoms of the disease usually resolve without treatment in one to four months. Sometimes, your spleen or liver may enlarge, and you may have to limit your activity until these organs return to normal size. Heart problems or involvement of the central nervous system occur only rarely. Infectious mononucleosis may cause severe liver failure in males with a very rare special XLP gene. In this case, mononucleosis can be fatal.
Is mononucleosis really a "kissing disease"?
The spread of EBV requires intimate contact with saliva (found in the mouth) of an infected person. Kissing can transmit infection, but saliva on toys, drink containers or hands can also transmit the virus. Transmission through the air or blood does not normally occur. The incubation period, the time from infection to appearance of symptoms, ranges from 4 to 6 weeks.
People who have infectious mononucleosis may be able to spread the infection to others for a period of weeks. Many healthy people can carry and spread the virus intermittently for life, and testing them for the virus is not practicable. For this reason, it is almost impossible to prevent the spreading of the virus.
Does Epstein-Barr virus cause chronic fatigue syndrome?
Can I get infectious mononucleosis more than once?
Although the symptoms of infectious mononucleosis usually go away in 1 or 2 months, EBV remains inactive in a few cells in the body for the rest of the person's life. Periodically, the virus can reactivate, and it is commonly found in the saliva of infected persons, particularly if they are immunosuppressed. This reactivation usually occurs without symptoms of illness.
Can EBV cause other serious illnesses?