Cytomegalovirus (CMV) Infection

Most people infected with cytomegalovirus have no symptoms.

A few infected people feel ill and have a fever.

Infection with CMV, like that with Epstein-Barr virus (EBV, a type 4 herpesvirus), can cause a type of infectious mononucleosis Infectious Mononucleosis Epstein-Barr virus causes a number of diseases, including infectious mononucleosis. The virus is spread through kissing. Symptoms vary, but the most common are extreme fatigue, fever, sore throat... read more in adolescents and young adults. Both CMV and EBV mononucleosis cause fever and fatigue. But EBV also causes a severe sore throat. CMV does not.

An uninfected person who receives a transfusion of blood containing CMV and becomes infected can have a fever, and sometimes liver inflammation develops 2 to 4 weeks later.

In people with a weakened immune system Overview of the Immune System The immune system is designed to defend the body against foreign or dangerous invaders. Such invaders include Microorganisms (commonly called germs, such as bacteria, viruses, and fungi) Parasites... read more , CMV can cause serious disease or death.

In people with AIDS Acquired immunodeficiency syndrome (AIDS) Human immunodeficiency virus (HIV) infection is a viral infection that progressively destroys certain white blood cells and is treated with antiretroviral medications. If untreated, it can cause... read more , CMV infection is a common viral complication. The virus can infect the retina of the eye. This infection (CMV retinitis) can cause blindness. Infection of the brain (encephalitis Encephalitis Encephalitis is inflammation of the brain that occurs when a virus directly infects the brain or when a virus, vaccine, or something else triggers inflammation. The spinal cord may also be involved... read more ), pneumonia Overview of Pneumonia Pneumonia is an infection of the small air sacs of the lungs (alveoli) and the tissues around them. Pneumonia is one of the most common causes of death worldwide. Often, pneumonia is the final... read more , or painful ulcers of the intestine or esophagus may also develop.

If a pregnant woman transmits CMV to the fetus, the following may result:

In newborns, CMV infection may cause extensive damage to the liver or brain. Newborns who survive may have hearing loss and intellectual disability.

Cytomegalovirus infection may not be recognized immediately. Diagnosis of CMV infection is often unnecessary in healthy adults and children because treatment is unnecessary. However, doctors consider the possibility of CMV infection in the following people:

Once CMV infection is suspected, a doctor conducts tests to detect the virus in body fluids or tissues.

In newborns, the diagnosis is usually made by sending a sample of urine to a laboratory to grow (culture) and identify the virus.

Blood tests that detect antibodies to CMV can confirm a new infection. (Antibodies Antibodies One of the body's lines of defense ( immune system) involves white blood cells (leukocytes) that travel through the bloodstream and into tissues, searching for and attacking microorganisms and... read more are produced by the immune system to help defend the body against a particular attacker, such as CMV.) But these tests cannot confirm whether disease is present. For instance, disease can be caused by reactivation of the virus, as in people with a weakened immune system. In these people, a biopsy of affected tissues is often necessary to confirm CMV disease.

Blood tests to estimate how many viruses are present may also be done.

CMV retinitis can be identified by an ophthalmologist, who examines internal eye structures to check for characteristic abnormalities using an ophthalmoscope Ophthalmoscopy A person who has eye symptoms should be checked by a doctor. However, some eye disorders cause few or no symptoms in their early stages, so the eyes should be checked regularly (every 1 to 2... read more .

Mild cytomegalovirus infection is usually not treated. It subsides on its own.

When the infection threatens life or eyesight, an antiviral drug Antiviral drugs A virus is composed of nucleic acid, either DNA or RNA, surrounded by a protein coat. It requires a living cell in which to multiply. A viral infection can lead to a spectrum of symptoms from... read more (valganciclovir, ganciclovir, cidofovir, foscarnet, or a combination) may be given. These drugs may be given by mouth or by vein. When CMV retinitis is very severe, the drugs may also be injected directly into the eye. These drugs have serious side effects (see table Some Antiviral Drugs for Herpesvirus Infections Some Antiviral Drugs for Herpesvirus Infections ) and do not cure the infection. However, treatment slows the disease's progression and may preserve sight.

Antiviral drugs are used to treat other severe symptoms due to CMV but are less reliably effective than when used to treat retinitis.

If CMV infection occurs in people whose immune system is temporarily weakened or suppressed (by a disorder or drug), the infection usually subsides when the immune system recovers or the drug is stopped.

Treating people who have HIV/AIDS Acquired immunodeficiency syndrome (AIDS) Human immunodeficiency virus (HIV) infection is a viral infection that progressively destroys certain white blood cells and is treated with antiretroviral medications. If untreated, it can cause... read more with drugs used to control HIV (antiretroviral drugs Antiretroviral Treatment of Human Immunodeficiency Virus (HIV) Infection Antiretroviral medications used to treat human immunodeficiency virus (HIV) infection aim to do the following: Reduce the amount of HIV RNA (viral load) in the blood to an undetectable amount... read more ) helps protect against CMV infection.

People who have had an organ transplant Overview of Transplantation Transplantation is the removal of living, functioning cells, tissues, or organs from the body and then their transfer back into the same body or into a different body. The most common type of... read more are often given antiviral drugs (such as ganciclovir, valganciclovir, or foscarnet) to prevent CMV infection.