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

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
• CMV gastroenteritis
• CMV retinitis
• CMV pneumonia
• 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

The symptoms of CMV infection are similar to those of mononucleosis. In fact, in a small percentage of people with mononucleosis, CMV is the cause. The symptoms of primary CMV infection are:

• Fatigue
• General discomfort, uneasiness, or ill feeling (malaise)
• Joint stiffness
• Loss of appetite
• Muscle aches or joint pain
• Night sweats
• Prolonged fever
• Weakness
• Weight loss

In immunocompromised people, CMV can attack specific organs. The major symptoms of these organ-specific infections are:

Eye:

• Blindness
• Visual impairment

Lung:

• Pneumonia with impaired oxygen uptake (hypoxia)

Gastrointestinal:

• Diarrhea
• Ulcerations with bleeding

Brain:

• Coma
• Encephalitis with behavioral changes
• Seizures

Blood and urine tests can detect and measure substances specific to CMV. A tissue biopsy may also be done.

Several antiviral medications are available to treat CMV. These medicines require close monitoring for adverse reactions. Antiviral drugs can help stop the virus from copying itself within the body. However, the drugs do not eliminate the virus from the body.

CMV infection in an immunocompromised host can be life-threatening. The severity of the disease depends on the strength of the person's immune system. Research has shown that people who have had a bone marrow transplant have the highest mortality risk.

Any immunocompromised person, whether an HIV patient, organ transplant recipient, bone marrow transplant recipient, or medically immunosuppressed person, should seek medical advice if any signs of infection occur.

• Blindness
• Kidney impairment (from medications used to treat the condition)
• Low white blood cell count (from medications used to treat the condition)
• Meningitis
• Pneumonia

Call your health care provider if you are immunosuppressed and you have symptoms of CMV infection.

The following should be tested for CMV:

• Anyone who has symptoms of infectious mononucleosis, but has negative test results for mononucleosis and Epstein Barr virus
• Anyone who shows signs of hepatitis, but has negative test results for hepatitis A, hepatitis B, and hepatitis C