Acute cytomegalovirus (CMV) infection is a condition caused by a member of the herpesvirus family.

See also: Mononucleosis

Mononucleosis can be caused by several different viruses and a few types of bacteria. Unlike the more common form of mononucleosis, caused by the Epstein-Barr virus (EBV), acute CMV infection is caused by cytomegalovirus.

In most people with a normal immune system, CMV infection does not cause any symptoms. But some people with this infection develop a "mononucleosis syndrome."

The infection is spread by:

• Blood transfusions
• Respiratory droplets
• Saliva
• Sexual contact
• Urine

Some young children release the virus in their urine for a long period of time, even when they do not have symptoms. CMV infection may occur at any age. It most commonly develops between ages 10 - 35.

Most people are exposed to CMV early in life and do not realize it because they have no symptoms. People with a compromised immune system can have a more severe form of the disease.