At a Glance
Why Get Tested?
If your doctor suspects you presently have, or recently had, a cytomegalovirus (CMV) infection or if it is important to know if you have ever had a CMV infection – such as prior to receiving an organ transplant
When to Get Tested?
When a young adult, a pregnant woman, or an immune-compromised person has flu-like symptoms that suggest a CMV infection; when a newborn has multiple congenital abnormalities, unexplained jaundice or anemia, and/or when an infant has seizures or developmental problems that may be due to CMV; prior to receiving an organ transplant
A blood sample drawn from a vein in your arm for CMV antibody testing; to detect the virus itself, the sample may be blood, urine, sputum, amniotic fluid, cerebrospinal fluid, duodenal fluid, or other body tissue
Test Preparation Needed?
The Test Sample
What is being tested?
Cytomegalovirus (CMV) is a common virus that occurs widely throughout the population but rarely causes symptoms. In the United States, as many as 50-85% of adults have been infected with CMV. Most people are infected as children or as young adults and do not experience any significant symptoms or health problems.
CMV is found in many body fluids during an active infection, including saliva, urine, blood, breast milk, semen, vaginal secretions, and cerebrospinal fluid. It is easily transmitted to others through close physical contact or by contact with infected objects, such as diapers or toys. After the initial "primary" infection has resolved, CMV becomes dormant or latent - like other members of the herpes family. Cytomegalovirus remains in a person for the rest of his life without causing any symptoms, unless the person's immune system is significantly weakened. If this happens, the virus can reactivate.
CMV can cause notable health problems in three situations:
- In young adults, primary CMV infection may cause a flu-like or mononucleosis-type illness. This condition, which causes symptoms such as extreme fatigue, fever, chills, body aches and/or headaches, usually resolves within a few weeks.
- In infants, primary CMV infection may cause serious physical and developmental problems. This occurs when women are infected for the first time (primary infection) during pregnancy and then pass the infection to the developing baby across the placenta. Most newborns (about 90%) that are infected appear healthy at birth but may develop hearing or vision problems, pneumonia, seizures, and/or delayed mental development a few months later. A few babies may be stillborn, while others may have symptoms at birth such as jaundice, anemia, an enlarged spleen or liver, and a small head.
- In those with weakened immune systems, CMV could cause serious illness and death. This includes those with HIV/AIDS, those who have had organ or bone marrow transplants, and those undergoing chemotherapy treatment for cancer. People with compromised immune systems who become infected for the first time (primary infection) might experience the most severe symptoms, and their CMV infection may remain active. Those who have been exposed to CMV previously may reactivate their infection. This could affect their eyes (causing inflammation of the retina, which can lead to blindness), digestive tract (causing bloody diarrhea and abdominal pain), lungs (causing pneumonia with a non-productive cough and shortness of breath), and brain (causing encephalitis). There can also be spleen and liver involvement, and those who have had organ or bone marrow transplants may experience some degree of rejection. Active CMV also further depresses the immune system, allowing other secondary infections, such as fungal infections, to occur.
CMV testing involves either a measurement of CMV antibodies, immune proteins created in response to CMV exposure, or by the detection of the virus itself. The virus can be identified during an active infection by culturing CMV or by detecting the virus's genetic material (its DNA) in a fluid or tissue sample.
How is the sample collected for testing?
The sample required depends on the type of testing. Antibody testing requires a blood sample, obtained by inserting a needle into a vein in the arm. Viral detection may be done on a variety of samples, including urine, blood, or sputum. Some samples may require a special procedure to collect, such as amniotic fluid, duodenal fluid, cerebrospinal fluid, or body tissue (biopsy).
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.
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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
(Updated 2010 December 6) Cytomegalovirus (CMV) and Congenital CMV Infection, Interpretation of Laboratory Tests. Centers for Disease Control and Prevention [On-line information]. Available online at http://www.cdc.gov/cmv/clinical/lab-tests.html through http://www.cdc.gov. Accessed February 2011.
Akhter, K and Wills, T (Updated 2011 February 2). Cytomegalovirus. eMedicine [On-line information]. Available online at http://emedicine.medscape.com/article/215702-overview through http://emedicine.medscape.com. Accessed February 2011.
Hanson, K et al (Updated November 2010 ). Cytomegalovirus – CMV. ARUP Consult [On-line information]. Available online at http://www.arupconsult.com/Topics/CMV.html?client_ID=LTD through http://www.arupconsult.com. Accessed February 2011.
Mayo Clinic Staff (2009 May 1). Cytomegalovirus (CMV) infection. MayoClinic [On-line information]. Available online at http://www.mayoclinic.com/health/cmv/DS00938 through http://www.mayoclinic.com. Accessed February 2011.
Dugdale, D (Updated 2009 August 28). CMV serology test. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003546.htm. Accessed February 2011.
(Updated 2010 December 6) Cytomegalovirus (CMV) and Congenital CMV Infection, Testing and Diagnosis of CMV Infection. Centers for Disease Control and Prevention [On-line information]. Available online at http://www.cdc.gov/cmv/testing-diagnosis.html through http://www.cdc.gov. Accessed February 2011.
Pagana, K. D. & Pagana, T. J. (© 2011). Mosby's Diagnostic and Laboratory Test Reference 10th Edition: Mosby, Inc., Saint Louis, MO. Pp 350-351.
Forbes BA, Sahm DF, Weissfeld AS. Bailey & Scott's Diagnostic Microbiology 12th Edition: Mosby Elsevier, St. Louis, MO; 2007, Pp 728, 764-766.
Blood Bank Guy – Transfusion Medicine Education. Is Leukocyte Reduction Equivalent to CMV-seronegative Products for Prevention of Transfusion-transmitted CMV? Available online at http://www.bbguy.org/faq/transfusion-transmitted-cmv.asp through http://www.bbguy.org. Accessed July 1, 2011.
CDC HIV/AIDS. You Can Prevent CMV. Available online at http://www.cdc.gov/hiv/resources/brochures/cmv.htm through http://www.cdc.gov. Accessed July 1, 2011.
Sources Used in Previous Reviews
Thomas, Clayton L., Editor (1997). Taber's Cyclopedic Medical Dictionary. F.A. Davis Company, Philadelphia, PA [18th Edition].
Pagana, Kathleen D. & Pagana, Timothy J. (2001). Mosby's Diagnostic and Laboratory Test Reference 5th Edition: Mosby, Inc., Saint Louis, MO.
(2002 October 26). Cytomegalovirus (CMV) Infection. National Center for Infectious Diseases [On-line information]. Available online at http://www.cdc.gov/ncidod/diseases/cmv.htm through http://www.cdc.gov.
(2004). Cytomegalovirus. ARUP’s Guide to Clinical Laboratory Testing [On-line information]. Available online at http://www.aruplab.com/guides/clt/tests/clt_a191.jsp#1372836 through http://www.aruplab.com.
Bonham, C. (2000). Prevention and Treatment of Cytomegalovirus Infection in Liver and Intestinal Transplantation. Medscape Transplantation 1(2), 2000 [From 'Nonsurgical Issues in Liver Transplantation,' a conference sponsored by MedImmune, Inc., Miami, Florida, June 2-4, 2000]. Available online at http://www.medscape.com/viewarticle/408776 through http://www.medscape.com.
(2004) Cytomegalovirus Infection in Pregnancy. March of Dimes, Professionals and Researchers, Quick Reference and Fact Sheets [On-line information]. Available online at http://www.marchofdimes.com/professionals/681_1195.asp through http://www.marchofdimes.com.
Muir, A. (2002 January 29). CMV - gastroenteritis/colitis. MEDLINEplus Health Information, Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/000667.htm.
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Kotton, C. (2002 February 22). CMV retinitis. MEDLINEplus Health Information, Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/000665.htm.
Spruance, S. Cytomegalovirus Infection. The Merck Manual – Second Home Edition [On-line information]. Available online at http://www.merck.com/pubs/mmanual_home2/sec17/ch198/ch198g.htm through http://www.merck.com.
Cytomegalovirus (CMV) DNA by PCR, Qualitative. LabCorp Facets [On-line information].
Rawlinson, W. and Scott, G. (2003 October). Cytomegalovirus, A common virus causing serious disease. Australian Family Physician Vol. 32, No. 10.
Brennan, C. (2001). Cytomegalovirus in Renal Transplantation. J Am Soc Nephrol 12:848-855 [On-line journal]. Available online at http://www.jasn.org/cgi/content/full/12/4/848 through http://www.jasn.org.
Pagana, Kathleen D. & Pagana, Timothy J. (© 2007). Mosby's Diagnostic and Laboratory Test Reference 8th Edition: Mosby, Inc., Saint Louis, MO. Pp 345-346.
Clarke, W. and Dufour, D. R., Editors (2006). Contemporary Practice in Clinical Chemistry, AACC Press, Washington, DC. Pp 1216-1217.
Wu, A. (2006). Tietz Clinical Guide to Laboratory Tests, Fourth Edition. Saunders Elsevier, St. Louis, Missouri. Pp 1551-1553.
(2006 February 6). About CMV. CDC [On-line information]. Available online at http://www.cdc.gov/cmv/facts.htm through http://www.cdc.gov. Accessed on 12/9/07.
(2006 March 28). Frequently Asked Questions about CMV. CDC [On-line information]. Available online at http://www.cdc.gov/cmv/faqs.htm through http://www.cdc.gov. Accessed on 12/9/07.
(2006 February 6). Signs and Symptoms of CMV. CDC [On-line information]. Available online at http://www.cdc.gov/cmv/signs.htm through http://www.cdc.gov. Accessed on 12/9/07.
(2006 February 6). CMV Tests for You and Your Baby. CDC [On-line information]. Available online at http://www.cdc.gov/cmv/testing.htm through http://www.cdc.gov. Accessed on 12/9/07.
(2005 November 4). CMV Diagnosis. CDC [On-line information]. Available online at http://www.cdc.gov/cmv/diagnosis.htm through http://www.cdc.gov. Accessed on 12/9/07.
(2007 February 12). Neurological Consequences of Cytomegalovirus Infection Information Page. NINDS [On-line information]. Available online at http://www.ninds.nih.gov/disorders/cytomegalic/cytomegalic.htm through http://www.ninds.nih.gov. Accessed on 12/23/07.
CMV - immunocompromised host. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/000663.htm. Accessed on 12/23/07.