What Is CMV (Cytomegalovirus)?

CMV or cytomegalovirus is a common virus that is spread through body fluids such as saliva, tears, blood, urine, breast milk, semen, and vaginal fluids. Once you are infected with CMV, you are infected for life. CMV infections occur in an active stage when you first acquire it and then it goes into a latent stage. Your CMV infection may stay in a latent stage or it may eventually reactivate, but there is little known as far as what causes CMV to reactivate.

Symptoms

Most CMV infections have no symptoms. When CMV does cause symptoms, you commonly will have one or more of the following symptoms, which you will notice can be associated with many other illnesses:

• fever
• swollen lymph nodes and glands
• sore throat
• tiredness

Because these same symptoms can be found in many other illnesses, you may have CMV or have become infected at some point in your life and not have been diagnosed with the virus. In non-pregnant people and people with healthy immune systems, CMV infection is usually not a concern.

Prevalence

CMV is commonly acquired in childhood to adolescent years with about 40 to 100 percent of people acquiring it by adulthood. So it is an extremely common infection. It is difficult to fully know the extent of people carrying the virus due to the symptoms being related to so many other things that people commonly have. As previously mentioned a large portion of individuals who acquire a CMV infection are never actually tested for it.

Both men and women carry equal risk of acquiring CMV as all populations are generally at risk. While CMV is generally not problematic, if you have a weakened immune system (HIV, transplant, etc.) you will be more prone to having symptoms of a CMV infection and in extreme cases complications. If you are a woman and pregnant with an active infection, you may also pose a risk of passing on CMV to your infant.

Congenital CMV

Congenital CMV occurs when a pregnant woman becomes infected with cytomegalovirus and then passes the infection on to her baby. This is perhaps the most dangerous form of CMV infection. According to the CDC, approximately 1 in 150 children born in the United States is born with CMV. The infection can cause temporary and permanent disabilities including:

• liver problems (including jaundice)
• spleen problems
• purple spots on the skin
• lung problems
• low birth weight and small head size
• seizures
• permanent hearing loss
• permanent vision loss
• mental disabilities and lack of coordination

About 33% of pregnant women infected with CMV pass the disease on to their unborn child. Symptoms may be present at birth or sometimes may not occur until the child has grown. If you know you contracted CMV during the course of your pregnancy, you should have your child screened for the above complications, especially hearing and vision loss.

Routine testing of babies for CMV in utero or right after birth is not recommended. Congenital CMV only occurs if the woman becomes infected during her pregnancy. If the baby contracts CMV after birth they are not at risk for developing complications.

Diagnosis

Cytomegalovirus can be diagnosed using a simple blood test that looks for antibodies against the virus or by measuring actual CMV viral levels in the blood. While it is easy to detect this virus, it is difficult to pinpoint the time at which a person has been infected. If a pregnant woman tests positive for CMV it may be difficult to determine whether the infection was present before or contracted during her pregnancy.

Treatment

Unfortunately, there is no cure for CMV. Antiviral drugs are too toxic to be given to pregnant women. Research is currently being conducted in an effort to create a vaccine that will prevent CMV. There has also been some research supporting the use of the antiviral drug ganciclovir after a child is born to prevent hearing loss.