Definition of CMV - immunocompromised host:

Cytomegalovirus (CMV) is a member of a group of herpes-type viruses that can cause disease in different parts of the body in people. This article discusses CMV in people with weakened immune systems.

Causes, incidence, and risk factors:

Most humans are exposed to CMV in their lifetime, but typically only individuals with weakened immune systems become ill from CMV infection. Usually, CMV produces no symptoms. However, serious CMV infections can occur in people with weakened immune systems due to AIDS, organ transplants, bone marrow transplant, chemotherapy, or medicines that suppress the immune system.

A CMV infection may affect different parts of the body. Infections include:

• CMV esophagitis (infection of the esophagus)
• CMV gastroenteritis (infection of the stomach or intestines)
• CMV retinitis (infection of the eye)
• CMV pneumonia (infection of the lung)
• Mononucleosis-like illness

Once a person becomes infected, the virus remains alive, but usually dormant, within that person's body for life. Rarely does it cause recurrent disease, unless the person's immune system is suppressed due to medication or disease. Therefore, for most people, CMV infection is not a serious problem.

Primary CMV infection in pregnant women can cause harm to the developing fetus. See: Congenital cytomegalovirus