Search form

Cytomegalovirus

Human Cytomegalovirus (HCMV) is a member of the Herpesviridae family of viruses which are large DNA viruses.  HCMV is also referred to as human herpesvirus type 5 (HHV-5) and belongs to the Betaherpesvirinae subfamily that includes human herpesviruses types 6 and 7 (HHV-6 and HHV-7).  HCMV infection is typically asymptomatic in healthy people, but it can cause a mononucleosis-like syndrome or hepatitis. HCMV is found throughout all geographic locations and socioeconomic groups and between 50% and 80% of adults in the United States have been infected.  Evidence of past infection can be shown by the presence of HCMV-specific antibodies. Like all herpesviruses, HCMV can become latent in an infected person and remains present in the body throughout the remainder of life.

Infection of immunocompromised patients such as HIV-infected persons, bone marrow or organ transplant recipients, can be very serious including severe life-threatening pneumonia. HCMV can also reactivate from latency in the immunocompromised. HCMV can be transmitted from an infected pregnant woman to a developing fetus and represents a significant viral cause of birth defects.  

Transmission

HCMV replicates in salivary glands and is transmitted primarily through contact with oral secretions of an infected person. It can also be transmitted from the blood of a pregnant woman across the placenta to the fetus. HCMV can also be transmitted via blood transfusion or from an organ transplant. HCMV can also be transmitted through sexual contact.

Prevention

There is not a vaccine for HCMV, but one is underdevelopment particularly for women of child-bearing age to prevent transmission to the fetus and possible birth defects. Pregnant women can take steps to reduce their risk of exposure to CMV and so reduce the risk of CMV infection of their fetus. Good hygiene such as hand washing and avoiding contact with saliva can reduce exposure to HCMV.

Diagnosis

A person who has been infected with cytomegalovirus (CMV) will develop antibodies to the virus that will stay in the body for the rest of that person’s life. A blood test for these antibodies can tell whether a person has been infected sometime in the past with CMV. To detect an active infection a test that detects the virus in urine, saliva, throat swab specimens or other body tissues either by viral culture or polymerase chain reaction (PCR) must be performed.

Treatment

There's no cure for CMV, and treatment for the virus generally is not recommended for healthy patients. Newborns and people with compromised immune systems do need treatment for symptomatic HCMV infection, such as pneumonia. Antiviral drugs such as ganciclovir are available that slow down the virus reproduction, but cannot eliminate the virus.

Recommended Reading

http://www.mayoclinic.com/health/cmv/DS00938/DSECTION=prevention

http://www.cdc.gov/cmv/index.html

Staras SA, Dollard SC, Radford KW, Flanders WD, Pass RF, Cannon MJ (November 2006). "Seroprevalence of cytomegalovirus infection in the United States, 1988–1994"Clin. Infect. Dis. 43 (9): 1143–51.