Cytomegalovirus is related to the viruses that cause chickenpox, herpes simplex and mononucleosis. Once you're infected with CMV, the virus remains with you for life, but it's not always active. CMV may cycle through periods during which it lies dormant and then reactivates. If you're healthy, it mainly stays dormant. You can pass the virus to others during reactivation.

Transmission of the virus occurs through exposure to body fluids — including blood, urine, saliva, breast milk, tears, semen and vaginal fluids — not by casual contact.

The virus can spread in a number of ways:

  • Touching your eyes or the inside of your nose or mouth after coming into contact with the body fluids of an infected person. This is the most common way CMV is spread because it's absorbed through the mucous membranes.
  • Through sexual contact with an infected person.
  • Through the breast milk of an infected mother.
  • Through organ transplantation or blood transfusions.
  • Through the placenta, from an infected mother to her unborn child, or during birth.
Apr. 04, 2014

You Are ... The Campaign for Mayo Clinic

Mayo Clinic is a not-for-profit organization. Make a difference today.