What is cytomegalovirus (CMV) infection?

Cytomegalovirus (CMV) infection has increasingly drawn clinical attention. Because infected cells become enlarged—forming characteristic “giant cells”—and contain intracytoplasmic and intranuclear inclusion bodies, this condition is also known as cytomegalic inclusion disease. Since CMV can cause intrauterine infection leading to stillbirth, spontaneous abortion, preterm delivery, and congenital malformations, prevention and control of this disease significantly impact eugenics, healthy birth practices, and overall population health. So, what exactly is cytomegalovirus infection? The following section provides a detailed explanation.

What Is Cytomegalovirus Infection?

Cytomegalovirus infection is an infectious disease caused by a DNA virus belonging to the herpesvirus family. Upon infection, the virus induces marked enlargement of host cells—hence its name, “cytomegalovirus.” Following infection, CMV may cause systemic disease, predominantly affecting the genitourinary system, central nervous system, and liver—ranging from asymptomatic infection to severe disability or death. CMV commonly establishes latent infection in humans, persisting in sites such as the salivary glands, mammary glands, kidneys, cervix, testes, leukocytes, and other glandular tissues. The virus may be shed continuously or intermittently in saliva, breast milk, urine, semen, and cervical secretions.

Knowledge Expansion: Modes of CMV Transmission

1. Sexual Transmission

CMV is frequently present in urinary tract secretions—including urine and semen—as well as in saliva; thus, it can be transmitted via sexual contact.

2. Contact Transmission

Both symptomatic CMV-infected individuals and asymptomatic carriers serve as sources of infection. The virus may be excreted in saliva, urine, semen, breast milk, and vaginal secretions. Direct contact with these bodily fluids—or with surfaces contaminated by CMV—can result in transmission. Additionally, CMV may spread through blood transfusion or surgical procedures involving blood exposure.

3. Mother-to-Child Transmission

During maternal pregnancy, CMV can cross the placenta and infect the fetus—a common form of intrauterine infection. During vaginal delivery, the virus may also be transmitted to the newborn via the birth canal. Furthermore, breastfeeding for over one month carries a CMV infection risk of 40–60%.

The above provides an overview of cytomegalovirus infection. We hope this information proves helpful.