HCMV Life Cycle

Human Cytomegalovirus, or HCMV, is a common form of herpes virus. According to the Merck Manual, blood tests indicate that 60 to 90 percent of adults have been infected at some time. It occurs frequently in salivary glands, although it can infect the entire body. HCMV is found in all areas of the world and in all socioeconomic strata.

Initial Infection

• The HCMV virus is spread through body secretions by both sexual and nonsexual means. Infected people have the virus in their urine, saliva, vaginal secretions, semen and breast milk for months after the initial infection. The disease may also be acquired through infected blood transfusions or organ transplants. While HCMV is not very contagious, it is often easily spread by children within school or day-care environments.

  Once within the host, the virus will fuse to the plasma membrane of a permissive cell in the host.

The Cellular Stage

• The virus will then enter into the cytoplasm of the cell and move on to the nucleus. The virus gains entry to the nucleus and deposits viral DNA. The virus then replicates its genome within the nucleus. Once complete, virus particles will leave the cell, entering into the surrounding tissues and infecting other cells within the host. This is a cyclical process.

The Infectious Stage

• Once the virus has proliferated, it will be shed into bodily secretions, often without the host exhibiting any signs or symptoms. The virus is spread to uninfected hosts by contact with these secretions. Once acquired, the infection remains within the host for life.

Symptoms

• Usually, people infected with the virus are asymptomatic, but some may experience symptoms similar to that of mononucleosis, including fatigue, general malaise, fever, swollen glands, muscle and joint pain and anorexia. More serious symptoms can occur in people with compromised immune systems, including visual impairment and blindness, pneumonia, diarrhea, hepatitis and central nervous system involvement leading to seizures and coma. In infected pregnant women, HCMV can cause congenital birth abnormalities that may lead to hearing and vision loss, lung, liver, spleen, and bleeding problems, as well as growth problems. HCMV has also been implicated in cases of autism.

Diagnosis, Treatment and Prevention

• Blood tests searching for specific antibodies are used to detect infection. Viral cultures can also be used to confirm the diagnosis.

  At this time there is no cure for HCMV. For normal, healthy children and adults, no treatment is necessary. Newborns and people with compromised immune systems will require treatment. Antiviral drugs may help slow down infection, though they are not a cure. Experimental vaccines are under investigation.

  To reduce the risk of infection, wash your hands often with soap and water. It is recommended that you avoid contact with the tears and saliva of young children. Avoid contact with contaminated articles, such as glasses and silverware that have come in contact with bodily fluids of an infected person. HCMV can also be transmitted through sexual contact. Exercising safe sex practices can reduce the risk of infection.