Cytomegalovirus Infection (CMV)

Alternative name :- Congenital CMV, Congenital cytomegalovirus

Cytomegalovirus (CMV) infection is caused by the cytomegalovirus, a deoxyribonucleic add, ether-sensitive virus belonging to the herpes family. CMV infection occurs worldwide and is transmitted by human contact. About four out of five people over age
35 have been infected with CMV, usually during childhood or early adulthood.1n most of these people, the disease is so mild that it's overlooked. However, CMV infection during pregnancy can be hazardous to the fetus, possibly leading to stillbirth, brain damage, and other birth defects or to severe neonatal illness. About 1 % of all neonates have CMV. It's the most common cause of congenital infection. In the United States. It's also common in those with human immunodefidency virus infection or in those who are otherwise innnunocompromised.

Once a person has had a first CMV infection, the virus lies dormant in the body throughout life, and can be reactivated. Usually, a reactivated infection causes few or no symptoms. When signs and symptoms do appear, they may be similar to those seen in infectious mononucleosis.

What Causes Cytomegalovirus Infection?

CMV has been found in saliva, urine, semen, breast milk, feces, blood. and vaginal and cervical secretions of infected people. The virus is usually transmitted through contact with these infected secretions, which harbor the virus for months or even years. It may be transmitted by sexual contact and can travel across the placenta, causing a congenital infection. Immunosuppressed patients, especially those who have received transplanted organs, have a 90% chance of contracting CMV infection. Recipients of blood transfusions from donors with positive CMV antibodies are at some risk.

Symptoms of Cytomegalovirus Infection

CMV is thought to spread through the body in lymphocytes or mononuclear cells to the lungs, liver, GI tract, eyes, and central nervous system, where it commonly produces inflammatory reactions.

Most patients with CMV infection have mild, nonspecific complaints or none at all, even though antibody titers indicate infection. In these patients, the disease usually runs a self limiting course. However, immunodeficiency patients and those receiving immunosuppressants may develop pneumonia or other secondary infections. In patients with acquired immunodeficiency syndrome, disseminated CMV infection may cause chorioretinitis (resulting in blindness), colitis, encephalitis. abdominal pain, diarrhea, or weight loss. Infected infants ages 3 to 6 months usually appear asymptomatic, but may develop hepatic dysfunction, hepatosplenomegaly, spider angiomas, pneumonitis, and lymphadenopathy.

Congenital CMV infection is seldom apparent at birth, although the neonate's urine contains the virus. CMV can cause brain damage that may not show up for months after birth. It can also produce a rapidly fatal neonatal illness characterized by jaundice, petechial rash, hepatosple. nomegaly, thrombocytopenia, hemolytic anemia, microcephaly. psychomotor retardation, mental deficiency, and hearing loss. Infants with congenital CMV infection may also present with abnormal muscle tone, lethargy, and chorioretinitis. Occasionally, this form is rapidly fatal.

In some adults. CMV may cause cytomegalovirus mononucleosis, with 3 weeks or more of irregular, high fever. Other findings may include a normal or elevated white blood cell (WBC) count, lymphocytosis, and increased atypical lymphocytes.

Diagnosis information

Although virus isolation in urine is the most sensitive laboratory method, diagnosis can also rest on virus isolation from saliva, throat, cervix, WBC, and biopsy specimens.

Other laboratory tests support the diagnosis of CMV, including complement fixation studies, hemagglutination inhibition antibody tests and, for congenital infections, indirect immunofluorescent tests for CMV immunoglobulin M antibody.

Treatment of Cytomegalovirus Infection

There is no current treatment for maternal CMV infection or for the congenital disease in the neonate. Rather, treatment aims to relieve symptoms and prevent complications. In the immunosuppressed patient, CMV is treated with acyclovir, ganciclovir and, possibly, foscamet. (Note: Ganciclovir is the only drug approved by the Food and Drug Administration for prevention and maintenance treatment of CMV and CMV retinitis.) Most important, parents of children with severe congenital CMV infection need support and counseling to help them cope with the possibility that their child will suffer serious and chronic medical problems or even death.

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Home Treatment

CMV "mononucleosis" is usually a fairly mild illness and can be treated at home, with rest and nonprescription medications suggested by your child's doctor.

Duration

Duration varies depending on the type of infection and the age and general health of the patient. For example, serious CMV infections before birth may cause developmental problems that affect a child for a lifetime. On the other hand, infection in teens may last only 2 to 3 weeks and cause no lasting problems. CMV infection can be life-threatening and can require many weeks of hospital treatment in children who are receiving organ transplants, or who have cancer or illnesses that affect the immune system (such as AIDS).

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Special considerations or prevention

To help prevent CMV infection:

• For patients taking gandclovir, monitor complete blood count because the drug causes bone marrow suppression. Administer G-CSF (Neupogen) or erythropoietin (Procrit), as ordered.
• Encourage vaccination for hepatitis and the flu to prevent further complications and opportunistic infections.
• For those who work closely with children, especially pregnant women, handwashing is essential and effective at reducing the risk of infection from exposure to CMV.
• Monitor the patient for thrush and encourage antifungal prophylaxis.
• Not sharing eating utensils with young children and avoiding kissing or intimate contact with CMV-positive individuals is also important.