CMV - pneumonia

Definition

Cytomegalovirus (CMV) is a member of a group of herpes-type viruses that can cause an infection of the lungs in immune-suppressed persons. This infection is particularly common in solid organ transplant and bone marrow transplant recipients.

Causes, incidence, and risk factors

Infection with CMV is very common. The majority of healthy adults have antibodies (an indication of previous infection) to CMV in their blood.

Usually CMV produces no symptoms, but serious CMV infections can occur in people with impaired immunity, such as those with AIDS, an organ transplant, or  bone marrow transplant, and people receiving chemotherapy or other immunosuppressive treatments.

CMV disease is a common complication of organ transplantation. CMV pneumonia occurs in 20% of bone marrow transplant recipients. Risk of infection is greatest from 5-13 weeks after transplantation.

Complications of CMV infection in individuals with AIDS include: an infectious, mononucleosis-like illness (CMV mononucleosis); CMV pneumonia; inflammation of the retina (CMV retinitis); and intestinal disease. In addition, CMV may increase the replication of HIV in infected individuals.

CMV pneumonia is associated with fever, a non-productive cough, and shortness of breath (dyspnea). Decreased oxygen levels in the blood (hypoxemia) in association with CMV pneumonia often predicts the patient will die, especially when mechanical ventilation is required.

Symptoms

• cough
• shortness of breath
• shortness of breath on exertion
• fever
• general discomfort, uneasiness, or ill feeling (malaise)
• loss of appetite
• fatigue
• sweating, excessive (night sweats)
• muscle aches or joint pains

Signs and tests

• urine culture (clean catch)
• blood culture
• CMV serology by IFA
• bronchoscopy with biopsy, stains, and culture for CMV
• chest x-ray
• arterial blood gas
• CMV PCR - a test to detect the presence of and amount of CMV in the blood
• CMV antigenemia - a test to detect viral particles on the surface of white blood cells (this can tell you if the virus is actively replicating in the body, or simply present in a dormant state)

Treatment

The objective of treatment is to stop the replication of the virus within the body through the use of antiviral agents, such as ganciclovir or foscarnet (which are both given intravenously, directly into a vein) and valganciclovir (which is taken orally). Oxygen therapy and breathing support with a ventilator may initially be necessary to maintain oxygenation until the infection is brought under control.

Expectations (prognosis)

Antiviral medications stop the replication of the virus, but do not destroy it. CMV is, in itself, immunosuppressive and may increase the risk of other infections due to the additive immunosuppression.

Complications

• relapse of infection
• overwhelming infection not responsive to treatment
• low white blood cell count with use of ganciclovir
• kidney impairment with use of foscarnet

Calling your health care provider

Call your health care provider if symptoms of CMV pneumonia occur.

Prevention

Use of CMV-negative donors for seronegative recipients of organ transplants, use of CMV-negative blood products for transfusion, and CMV-immune globulin in certain patients has shown some preventive effects. Prevention of AIDS avoids opportunistic diseases, including CMV, associated with a damaged or incompetent immune system.

Illustrations

CMV pneumonia

Antibodies

Page Content:

Pneumonia - cytomegalovirus; Cytomegalovirus pneumonia; Troll of transplantation