Cytomegalovirus (CMV) is a common virus that is part of the family of herpes viruses. It infects most people at some point in their lives. It can be spread to children through body fluids like saliva, tears, urine, blood, and even breast milk. It is often transmitted during diaper changes, while bathing, and during other close contact. Teenagers and adults transmit the virus during close contact such as kissing and sexual intercourse.
Cytomegalovirus is responsible for the most common congenital (present at birth) infection in the United States. Infants can contract CMV infections from their infected mothers, sometimes before birth when the virus is passed to the fetus through the placenta, or during delivery if the mother’s genital tract is infected. It can also be transmitted through CMV-infected breast milk.
Children who have a human immunodeficiency virus (HIV) infection or whose immune system is weakened for another reason (e.g., because of cancer treatment) are also particularly susceptible to CMV infections and their complications.
Once a person is infected, CMV stays within the person, usually in a resting or inactive (latent) state, and can intermittently become active and appear in that person’s secretions. The virus can reactivate and cause illness if a person’s immune system becomes weakened by a disease or medicine.
Signs and Symptoms
When a child contracts a CMV infection, he usually has mild symptoms or even no symptoms at all. However, some infections do cause symptoms. For example, when teenagers develop a CMV infection, it can look like infectious mononucleosis because of the prolonged fever, sore throat, body aches, and fatigue.
Most babies born with a CMV infection have no apparent symptoms at birth and remain well. However, a few are found to have hearing loss or a learning disability. In a smaller number of cases, these babies have symptoms at birth such as low birth weight, jaundice (yellowing of the skin and eyes), swollen lymph nodes, and a skin rash. These babies are likely to have problems throughout life such as deafness and mental retardation. In children with weakened immune systems, CMV infection can affect many organs of the body including the lungs, liver, kidneys, bone marrow, and bowels. In children with organ transplants, CMV infections are linked with rejection or malfunction of the transplant.
The incubation period for most CMV infections is between 4 and 16 weeks.
How Is the Diagnosis Made?
Evidence of a CMV infection can be found through special viral cultures of urine, saliva, or other body fluids. Blood tests will show whether a person has made antibody to the virus. There are a variety of special tests that measure parts of the virus and allow doctors to predict whether CMV is the cause of a particular illness.
In most children, there is no need for specific treatment for CMV infections. However, serious infections in children with weakened immune systems, such as those with HIV infection or an organ transplant, can be treated with a medicine called ganciclovir. Studies are being done to see if treatment of newborns with serious CMV infection may be helpful.
What Is the Prognosis?
Most children with CMV infections remain symptom free and lead completely normal lives, even though the virus remains inactive in the body. However, youngsters who contract a CMV infection at birth may develop a hearing impairment or mental retardation.
Good personal hygiene habits, particularly regular hand washing, can lower the risk of spreading CMV. When you’re caring for a child with a CMV infection, be sure to wash your hands frequently, particularly after changing diapers. Most children with CMV have no symptoms but do pass the virus in their urine, so it is important to remember to wash your hands every time you change a child’s diaper. Children should be told not to share their cups and utensils because they are contaminated with saliva and can spread viruses from person to person.