Definition of CMV - pneumonia:

Cytomegalovirus (CMV) pneumonia is an infection of the lungs that can occur in people who have a suppressed immune system.

See also:

• CMV esophagitis
• CMV gastroenteritis
• CMV retinitis
• Cytomegalovirus - immunocompromised host
• Congenital cytomegalovirus

Causes, incidence, and risk factors:

CMV pneumonia is caused by a member of a group of herpes-type viruses. Infection with CMV is very common. Most healthy adults have antibodies (indicating previous infection) to CMV in their blood.

Usually CMV produces no symptoms, but serious CMV infections can occur in people with impaired immunity from conditions such as:

• AIDS
• Bone marrow transplant
• Organ transplant
• Chemotherapy or other treatments that suppress the immune system

In people who have had organ and bone marrow transplants, the risk of infection is greatest 5 - 13 weeks after the transplant.

Symptoms:

• Cough
• Fatigue
• Fever
• General discomfort, uneasiness, or ill feeling (malaise)
• Loss of appetite
• Muscle aches or joint pains
• Shortness of breath
• Shortness of breath on exertion
• Sweating, excessive (night sweats)

Low oxygen levels in the blood (hypoxemia) with CMV pneumonia often predicts death, especially in patients who need mechanical ventilation.

Signs and tests:

• Arterial blood gas
• Blood culture
• Blood tests to detect and measure substances specific to CMV infection
• Bronchoscopy with biopsy
• Chest x-ray
• Urine culture (clean catch)

Treatment:

The objective of treatment is to stop the virus from copying in the body through the use of antiviral drugs. Some people will need to get medication through a vein (intravenous). Some people might initially need oxygen therapy and breathing support with a ventilator to maintain oxygen until the infection is brought under control.

Expectations (prognosis):

Antiviral medications stop the virus from copying itself, but do not destroy it. CMV itself suppresses the immune system, and may increase the risk of other infections due to the additional immunosuppression.

Complications:

Complications of CMV infection in people with AIDS include:

• CMV pneumonia
• Intestinal disease
• Infectious, mononucleosis-like illness (CMV mononucleosis)
• Inflammation of the retina (CMV retinitis)

CMV also increases the replication of HIV in people who are infected.

Complications of CMV pneumonia include:

• Kidney impairment (from drugs used to treat the condition)
• Low white blood cell count (from drugs used to treat the condition)
• Overwhelming infection that doesn't respond to treatment
• Relapse of infection

Calling your health care provider:

Call your health care provider if you have symptoms of CMV pneumonia.

Prevention:

The following have been shown to help prevent CMV pneumonia in certain patients:

• Using organ transplant donors who don't have CMV
• Using CMV-negative blood products for transfusion
• Using CMV-immune globulin in certain patients

Preventing AIDS avoids opportunistic diseases, including CMV, that can occur in people who have a damaged or poorly functioning immune system.