Human betaherpesvirus 5, also called human cytomegalovirus (HCMV), is species of virus in the genus Cytomegalovirus, which in turn is a member of the viral family known as Herpesviridae or herpesviruses.
Although they may be found throughout the body, HCMV infections are frequently associated with the salivary glands.
HCMV infection is typically unnoticed in healthy people, but can be life-threatening for the immunocompromised, such as HIV-infected persons, organ transplant recipients, or newborn infants.
After infection, HCMV remains latent within the body throughout life and can be reactivated at any time.
Eventually, it may cause mucoepidermoid carcinoma and possibly other malignancies such as prostate cancer and breast cancer.
HCMV is found in all geographic locations and all socioeconomic groups, and infects between 60% and 70% of adults in the first world and almost 100% in the third world.
Of all herpes viruses, HCMV harbors the most genes dedicated to altering (evading) innate and adaptive host immunity and represents a lifelong burden of antigenic T cell surveillance and immune dysfunction.
HCMV infection is more widespread in developing countries and in communities with lower socioeconomic status and represents the most significant viral cause of birth defects in industrialized countries.
Congenital HCMV is the leading infectious cause of deafness, learning disabilities, and intellectual disability in children.
Human betaherpesvirus 5 infection has a classic triad of symptoms:
- fever, peaking in the late afternoon or early evening;
- pharyngitis, usually exudative;
- symmetrical adenopathy.
Up to 5 of every 1,000 live births are infected
Five percent develop multiple handicaps, and develop cytomegalic inclusion disease with nonspecific signs that resemble rubella.
Another five percent later develop cerebral calcification (decreasing IQ levels dramatically and causing sensorineural **deafness **and psychomotor retardation).