Cytomegalovirus (CMV) Infection
What is CMV?
CMV is a virus within the herpes group of viruses, all of which tend to remain dormant in the body after an initial infection. An estimated 50% to 80% of adults have experienced infection and test reactive for CMV antibodies.
The majority of people infected with CMV experience no symptoms, and therefore are not aware that they have been infected. In adults, infection may occasionally manifest as mild flu-like symptoms, such as fever, swollen glands, and sore throat. However, infection of a fetus can lead to hearing loss, a variety of developmental problems, and in rare cases, death of the newborn.
If a person has CMV, their status may be active or past. An active infection indicates that they are experiencing an initial infection or a recurrent infection, and they are shedding the virus. This person is considered infectious. A past infection indicates that the person contracted the CMV virus in the past, but that infection is no longer considered active in their body and they are presumed non-infectious.
How is CMV Transmitted?
CMV can be transmitted through urine, saliva, mucus, cervical secretions, semen, blood, or breast milk. It is common in settings such as day care centers, where children can transmit the virus through contact with each other’s bodily fluids (infected children carry the virus in their respiratory and urinary tracts for long periods of time). Adults can also be infected through exchange of bodily fluids, including unprotected sexual contact. An infected mother can transmit CMV to her fetus either through the placenta or through exposure to her infected cervical secretions during birth.
How Are TSBC Donors Screened?
When an individual is exposed to CMV, they develop antibodies to the virus. We use these antibodies in the blood to test for the presence and status of CMV infection.
Blood testing can detect the presence of antibodies to CMV, which indicates whether the individual has ever been infected with the virus. This test is called the CMV total antibody test. If this test is positive, further testing can indicate the status of the infection. Further testing includes CMV immunoglobulin IgG and IgM, which are evaluated together.
All donors are tested quarterly as part of our ongoing donor screening. Information on a donor’s CMV antibody status is included on his short profile.
- CMV Total Antibody is negative: The donor is presumed to have no current or past CMV infection.
- CMV IgG is positive: This provides an informational picture of the donors CMV history, but is not used to determine current status. If both the CMV total antibody and the CMV IgG are positive, this shows a historic infection not a current infection.
- CMV IgM is negative: Donor is presumed non-infectious and eligible to donate sperm.
- CMV IgM is positive: Donor is presumed currently infectious. All quarantined vials from the last negative test are destroyed. The donor is put on hold for at least three months and is not eligible to donate until his CMV IgM results are negative, indicating he is no longer infectious.
Is It Safe to Use a Donor Who has a Positive CMV Total Antibody or IgG result?
Yes, it is. Our screening process aims to identify donors who are positive for a past history of CMV infection, but do not have an active infection. Furthermore, our six-month quarantine policy ensures that should a donor test positive for a current or recent infection, quarantined vials stored after the last negative test result are destroyed. Only quarantined vials with negative results before and after collection are released to recipients.
Should a Recipient Be Screened for CMV?
The CDC has no recommendation regarding CMV screening of recipients. We recommend that you check with your own medical provider regarding CMV testing before or during pregnancy.