Contraction and Symptoms

CMV Infection

CMV is contracted through the passage of bodily fluids from an infected human to an uninfected human. Contact can occur from many sources, such as through the placenta (during pregnancy), blood transfusions, breast milk, organ transplantation, saliva, urine, and sexual transmission. It is estimated that about 50-80 percent of the population will have contracted the virus by the age of 40.

The distinctive feature of CMV infection is enlargement of the cell and presence of viral inclusion bodies. Viral inclusion bodies are abnormal structures that can appear in the nucleus and/or cytoplasm during virus multiplication and can be important signals for diagnosing a viral infection.
When a human is first infected, CMV infects the epithelial cells in the salivary glands, which causes continuous infection and further reproduction and transmission of the virus to other cells in the body.
The presence of viral inclusion bodies ("owl eyes") can help diagnose the presence of a virus.


The symptoms of CMV are similar to those of the common cold and flu, therefore, many hosts are unaware they have been infected by the virus.

Healthy children that become infected with CMV either show no symptoms or very few symptoms. Most symptoms are mild and can include fever, fatigue, sore throat, and swollen glands. These symptoms can also characterize other common viral infections, so infection of CMV is typically not the first diagnosis. CMV remains dormant throughout a person’s life and has the possibility of reactivating, even if no symptoms were present during the first infection.

In individuals with weakened immune systems, the symptoms of CMV can be more severe. These can include high fever, pneumonia, hepatitis, encephalitis, myelitis, colitis, uveitis, retinitis, and neuropathy.

CMV is an extremely common virus around the world, but no severe epidemics have ever been recorded.

Congenital CMV Infection

Congenital (present at birth) CMV is passed from a mother to her baby during pregnancy. This is a very serious infection that can cause severe problems in a baby, including deafness, neurological problems, and death. CMV is the most common viral infection that infants are born with in the United States. Out of the 30,000 children born with CMV each year,
  • 5,000 experience severe permanent problems,
  • 24,000 have no symptoms, and
  • 1,000 experience mild, short-term symptoms.

If a mother contracts CMV while pregnant, this could lead to the passage of the virus into the fetus via the placental tissue, which has been shown to cause stillbirths.

Congenital CMV infection causes more long-term problems and childhood deaths than Down syndrome, fetal alcohol syndrome, and other common medical birth conditions.

Risk Factors

Individuals with a greater chance of contracting CMV include:
  • Daycare workers
  • Blood transfusion patients
  • People with multiple sex partners
  • Recipients of infected organs or bone marrow (from transplants)
  • Those with weakened immune systems (elderly, newborns, AIDS patients, etc.)