As the name indicates, cytomegalovirus (CMV) disease is a virus infection. It is caused by herpes virus type 5, and it takes two forms. Intrauterine infection of the fetus is a very serious, often lethal, condition that affects a small proportion (about 5–10%) of infants whose mothers contract the infection during pregnancy. In the United States this is about 0.5 to 1.0 percent of all pregnancies. When it is not fatal, the infant may suffer from permanent neurological damage, as well as damage to the eyes, liver, lungs, and other organs. CMV infection is also a serious risk following organ and bone-marrow transplants. The risk is greatest when the donor is seropositive (i.e. a carrier) and the recipient is seronegative. A third category of CMV infection can occur as a complication of AIDS (acquired immunodeficiency syndrome).
CMV is transmitted mainly by intimate personal contact of an infected and an uninfected mucosal surface during sexual intercourse, by body secretions, and in feces. The incubation period is several weeks, and infected individuals remain capable of transmitting the virus for many months, perhaps for life. Antiviral agents may arrest the progress of the disease, but by far the most important actions are preventive, including careful attention to hygiene at all times. Universal precautions are highly desirable in handling all suspected or potentially contaminated body secretions.
JOHN M. LAST