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Mono Test

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Also known as: Mononucleosis Spot Test; Mononuclear Heterophile Test; Heterophile Antibody Test; Monospot
Formal name: Heterophile Antibody Titer

At a Glance

Why Get Tested?

To detect and help diagnose infectious mononucleosis (mono)

When to Get Tested?

When a person, especially an adolescent, has symptoms of mononucleosis, including fever, sore throat, swollen glands, and fatigue

Sample Required?

A blood sample drawn from a vein in your arm

Test Preparation Needed?

None

The Test Sample

What is being tested?

Infectious mononucleosis, commonly called mono, refers to an infection caused by the Epstein-Barr virus (EBV). This test detects proteins in the blood called heterophile antibodies that are produced by the immune system in response to an EBV infection.

Infectious mononucleosis is characterized by a particular set of symptoms that most often affects adolescents. People who have mono often have a fever, sore throat, swollen glands, and fatigue. Many will also have an enlarged spleen, and a few may have an enlarged liver. Symptoms of the infection usually arise about one month after the initial infection and may last for several weeks. The associated fatigue may last for several months. Mono is usually a self-limiting condition; the symptoms resolve without any specific treatment.

Epstein-Barr virus is very common. According to the Centers for Disease Control and Prevention (CDC), up to 95% of people in the United States will have been infected by EBV by the time they are 40 years old. The virus is present in the saliva of an infected person and can be spread from person to person through close contact such as kissing and through sharing utensils or cups.

Most of the time, EBV infection occurs in childhood and causes few or no symptoms; however, if first exposure to the virus occurs in adolescence, it can cause symptoms associated with infectious mononucleosis in about half of those infected. Mono can affect anyone at any age, but its prevalence is highest in populations of young people, such as students in high schools or colleges, or in the military.

About 70% to 80% of those with mono produce heterophile antibodies, and these can be detected with a rapid screening mono test. These proteins are not specific for EBV but, when found in adolescents in conjunction with mono symptoms, they can be used to help diagnose infectious mononucleosis. If a mono test is negative and suspicion it still high, then a test specific for EBV antibodies may be performed.

A complete blood count (CBC) and blood smear are usually also performed, as mono is also characterized by a high white blood cell (WBC) count and the presence of atypical white blood cells (usually reported as reactive lymphocytes) as seen on a blood smear.

How is the sample collected for testing?

A blood sample is drawn by needle from a vein in the arm.

NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.

Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed.

The Test

Common Questions

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Article Sources

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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.

Sources Used in Current Review

Vorvick, L. (2012 May 15). Mononucleosis spot test. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003454.htm. Accessed November 2012.

Omori, M. (Updated 2012 May 23). Mononucleosis in Emergency Medicine. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/784513-overview through http://emedicine.medscape.com. Accessed November 2012.

Cunha, B. and Levy, C. (Updated 2011 September 21). Infectious Mononucleosis. Medscape Reference [On-line information]. Available online at http://emedicine.medscape.com/article/222040-overview through http://emedicine.medscape.com. Accessed November 2012.

Mayo Clinic Staff (2010 June 26). Mononucleosis. Mayo Clinic [On-line information]. Available online at http://www.mayoclinic.com/print/mononucleosis/DS00352/DSECTION=all&METHOD=print through http://www.mayoclinic.com. Accessed November 2012.

Vorvick, L. (2012 May 15). Mononucleosis MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/000591.htm. Accessed November 2012.

Hirsch, L. (Reviewed 2011 January). Mononucleosis. Nemours Foundation [On-line information]. Available online at http://kidshealth.org/parent/infections/common/mono.html through http://kidshealth.org. Accessed November 2012.

Pagana, K. D. & Pagana, T. J. (© 2011). Mosby's Diagnostic and Laboratory Test Reference 10th Edition: Mosby, Inc., Saint Louis, MO. Pp 683-684.

Kasper DL, Braunwald E, Fauci AS, Hauser SL, Longo DL, Jameson JL, eds (2005). Harrison's Principles of Internal Medicine, 16th Edition, McGraw Hill, Pp1046-1048.

Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. McPherson R, Pincus M, eds. Philadelphia, PA: Saunders Elsevier: 2007, Pp 555-556.

Sources Used in Previous Reviews

Pagana, Kathleen D. & Pagana, Timothy J. (2001). Mosby's Diagnostic and Laboratory Test Reference 5th Edition: Mosby, Inc., Saint Louis, MO. Pp 594-595.

Corbett, JV. Laboratory Tests & Diagnostic Procedures with Nursing Diagnoses, 4th ed. Stamford, Conn.: Appleton & Lang, 1996. Pp. 373-374.

Ebell, M. (2004 October 1). Epstein-Barr Virus Infectious Mononucleosis. American Family Physician [On-line journal]. Available online at http://www.aafp.org/afp/20041001/1279.html through http://www.aafp.org.

Schmid, S., Leader Herpesvirus Group (2005 September 13, Updated). Epstein-Barr Virus and Infectious Mononucleosis. CDC, National Center for Infectious Diseases [On-line information]. Available online at http://www.cdc.gov/ncidod/diseases/ebv.htm through http://www.cdc.gov.

National Center for Infectious Diseases. Epstein-Barr Virus and Infectious Mononucleosis. Available online at http://www.cdc.gov/ncidod/diseases/ebv.htm through http://www.cdc.gov.

Nebraska Health and Human Services System. Infectious Mononucleosis (Mono) Disease Fact Sheet. Available online at http://www.hhs.state.ne.us/epi/epimono.htm through http://www.hhs.state.ne.us.

Pagana, K. D. & Pagana, T. J. (© 2007). Mosby's Diagnostic and Laboratory Test Reference 8th Edition: Mosby, Inc., Saint Louis, MO. Pp 662-663.

Cunha, B. (Updated 2008 October 17). Infectious Mononucleosis. eMedicine [On-line information]. Available online at http://emedicine.medscape.com/article/222040-overview through http://emedicine.medscape.com. Accessed May 2009.

Omori, M. (Updated 2009 April 02). Mononucleosis. eMedicine [On-line information]. Available online at http://emedicine.medscape.com/article/784513-overview through http://emedicine.medscape.com. Accessed May 2009.

Smith, D. S. (Updated 2008 September 3). Mononucleosis. MedlinePlus Medical Encyclopedia eMedicine [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/000591.htm. Accessed May 2009.

Smith, D. S. (Updated 2008 September 3). Mononucleosis spot test. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003454.htm. Accessed May 2009.

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