Cytomegalovirus is a virus that causes different illnesses in different groups of people.
Cytomegalovirus, also known as CMV, is a common infection. Although lifelong, the virus usually remains quiet in the tissues of the body after the initial infection. It can, however, be shed in the mouth, urine, and genital tract, serving as a source of infection for other people. CMV can also cause a second, more severe infection if the immune system becomes weak for any reason.
Most people have been infected with CMV by the time they are adults. People with who are at risk for severe disease include: