CMV is a virus within the herpes group of viruses, all of which tend to remain dormant in the body after an initial infection. There are two types of CMV infection: primary and recurrent. A primary infection is an individual’s first infection. A recurrent infection is either a reactivation of a prior infection or a re infection with a new strain. An estimated 40% to 90% of adults have experienced infection and test positive for CMV antibodies.
The majority of people infected with CMV experience no symptoms and are therefore not even aware that they’ve been infected. In adults, infection may manifest in flu-like symptoms, such as fever, swollen glands, and sore throat. However, infection of a fetus or newborn can lead to brain damage or even death. Currently there is no effective treatment or vaccine.
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 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.
Is There a Way to Screen for CMV?
A blood test can detect the presence of antibodies to CMV, which would indicate whether an individual had ever been infected with the virus. The presence of IgM (immunoglobulin M) antibodies indicates that the individual is experiencing either a primary or a current infection. The presence of IgG (immunoglobulin G) antibodies (reactive) indicates that an infection occurred at some point in the past. Therefore, a reactive (positive) IgG and non-reactive (negative) IgM result would indicate that an individual had experienced a past infection is not necessarily currently infectious.