Cytomegalovirus

cytomegalovirus (CMV), any of several viruses in the herpes family (Herpesviridae), frequently involved in human infection. The virus is so named for the enlarged cells produced by active infections; these cells are characterized by the inclusion of foreign matter, especially in the nucleus. Cytomegalovirus (CMV) is distributed worldwide. It is especially prevalent in crowded communities and in unclean living environments.

CMV is not highly contagious. It is transmitted by sexual contact or exposure to infected body fluids. It rarely causes serious illness in otherwise healthy adults, only occasionally producing mononucleosis-like symptoms, such as fever, fatigue, and sore throat.

CMV is the most common cause of congenital infection of newborn infants, who acquire the virus either in the uterus or during birth. Symptomatic infections in 10 percent of congenital cases cause jaundice, fever, and enlargement of the spleen and liver. Whether symptomatic or not, CMV infections are a major cause of congenital deafness and have other long-range neurological consequences, including intellectual disability and blindness.

Infections in adults with compromised immune systems can cause an opportunistic severe pneumonia and inflammation of the retina leading to blindness; because these individuals have no natural defenses against the spread of the virus, such infections may be life-threatening.

Most individuals who are otherwise healthy and become infected with CMV do not require treatment; the infection typically is self-limiting. Antiviral medications may be used to treat persons with weakened immune systems and infants. Antivirals work by slowing viral reproduction, potentially lessening the severity of symptoms; the drugs are not curative.