Causes

Cytomegalovirus (CMV) is a herpes-type virus related to the virus that causes chickenpox. Infection with CMV is very common.

The infection is spread by saliva, urine, respiratory droplets, sexual contact, and blood transfusions. Most people are exposed to the virus in their lifetime, but it usually produces mild or no symptoms in healthy people.

However, serious CMV infections can occur in people with weakened immune systems. This includes patients receiving chemotherapy for cancer and patients on immune-suppressing medicines following an organ transplant.

In rare instances, more severe CMV infection involving the GI tract has been reported in people with healthy immune systems. When CMV colitis occurs in someone with a normal immune system, the person typically has other serious medical conditions such as a severe injury, kidney failure, or infection.

The following increase your risk for CMV gastroenteritis/colitis:

• AIDS
• Bone marrow or organ transplant
• Chemotherapy
• Medications that suppress the immune system

Symptoms

Gastrointestinal CMV disease may affect one area or the entire body. Ulcers can occur in the esophagus, stomach, small intestine, or colon. Such ulcers are associated with symptoms such as:

• Abdominal pain
• Difficulty swallowing or pain with swallowing
• Nausea
• Vomiting

When the intestines are involved, the ulcers may cause:

• Abdominal pain
• Bloody stools
• Diarrhea
• Fever
• Weight loss

More severe infections can result in gastrointestinal bleeding or a hole through the wall of the bowel.

Exams and Tests

Tests that may be done include:

• Barium enema
• Colonoscopy
• Esophagogastroduodenoscopy (EGD)
• Stool culture to rule out other causes of infection
• Upper GI and small bowel series

Laboratory tests will be done on a sample of tissue taken from your stomach or intestine. The tests, such as a gastric or intestinal tissue culture or biopsy, determine if the virus is in the tissue.

A CMV serology test is done to look for the virus in your blood.

Treatment

Treatment is meant to control the infection and relieve symptoms.

Medicines to fight the virus (antiviral medications) are prescribed. The medicines may be given through a vein (IV), and sometimes by mouth, for several weeks. The most commonly used medicines are ganciclovir and valganciclovir.

In some cases, long-term therapy may be needed. A medication called CMV hyperimmune globulin may be used when other drugs don't work.

Other medications may include:

• Drugs to prevent or reduce diarrhea
• Pain killers (analgesics)

Nutritional supplements or intravenous nutrition (putting nutrients directly into the blood stream) may be used to treat muscle loss due to the disease.

Outlook (Prognosis)

In people with healthy immune systems, symptoms usually go away without treatment.

Symptoms are more severe in those with weakened immune systems. The outcome depends upon the severity of the immune system deficiency and the severity of the CMV infection.

People with AIDS may have a worse outcome than those with weakened immune systems due to another reason. CMV infection typically affects the entire body, even if patients only have gastrointestinal symptoms. How well a patient does depends on how well the antiviral drugs work.

Possible Complications

The drugs used to fight the virus may cause side effects. The type of side effect depends on the specific drug used. For example, the drug ganciclovir may lower your white blood cell count. Another drug, foscarnet, may lead to kidney problems.

When to Contact a Medical Professional

Call for an appointment with your health care provider if you have symptoms of CMV gastroenteritis/colitis.

Prevention

There is a significant risk of CMV infection in people with no signs of the virus in their blood who receive an organ transplant from a CMV-positive donor. The antiviral drugs ganciclovir (Cytovene) and valganciclovir (Valcyte), taken by mouth before the transplant, can lower your chance of a new infection or reactivation of an old infection in such cases.

People with AIDS who are effectively treated with antiviral therapy are much less likely to get CMV infection.

Alternative Names

Colitis - cytomegalovirus; Gastroenteritis - cytomegalovirus; Gastrointestinal CMV disease

References

Young JH, Weisdorf DJ. Infections in recipients of hematopoietic cell transplantation. In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Infectious Diseases. 7th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2009:chap 311.

Update Date: 4/18/2012

Reviewed by: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; George F Longstreth, MD, Department of Gastroenterology, Kaiser Permanente Medical Care Program, San Diego, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.