Cytomegalovirus (CMV) is a virus related to the herpes virus. It is so common that almost all adults in developing countries and 50% to 85% of adults in the United States have been infected.
Usually CMV is a mild disease that does not cause any serious problems in healthy children and adults. Most people get flu-like symptoms or an illness similar to mononucleosis, if they develop symptoms at all.
Being infected with this virus can be serious and even fatal in some people, however, including:
People receiving chemotherapy for cancer
People with diseases that suppress the immune system, such as AIDS
People who have received organ or bone marrow transplants
Newborn babies of women infected with CMV during pregnancy
Women infected with CMV for the first time during pregnancy can pass the virus to their unborn babies in the womb. The virus can also pass from mother to baby in vaginal secretions during delivery and in breast milk after birth. The virus can pass from person to person through close personal contact, sexual contact, blood transfusion or organ transplantation.