Causes

CMV pneumonia is caused by a member of a group of herpes-type viruses. Infection with CMV is very common. 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, but serious CMV infections can occur in people with weakened immune systems 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.

Exams and Tests

• Arterial blood gas
• Blood culture
• Blood tests to detect and measure substances specific to CMV infection
• Bronchoscopy with biopsy
• Chest x-ray
• CT scan of chest
• 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 with CMV pneumonia will need to get medication through a vein (intravenously). Some people might initially need oxygen therapy and breathing support with a ventilator to maintain oxygen until the infection is brought under control.

Outlook (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.

Possible Complications

Complications of CMV infection in people with AIDS include:

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

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
• Return of infections

When to Contact a Medical Professional

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. People with AIDS who have a CD4 count of less than 100 should consider taking preventive treatment for CMV.

Alternative Names

Pneumonia - cytomegalovirus; Cytomegalovirus pneumonia

References

Drew WL. Cytomegalovirus. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 399.

Updated: 4/1/2012

Reviewed by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School, Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.