When does the initial infection with human cytomegalovirus most commonly occur?

The initial infection with human cytomegalovirus (HCMV) most commonly occurs in utero, through transplacental transmission from an infected mother. This means that the virus can be transmitted to the fetus during pregnancy, which is a significant mode of infection. Congenital infection can lead to serious complications in the newborn, including hearing loss, vision problems, and developmental disabilities.

HCMV is known for its ability to remain latent after the primary infection and can reactivate later, but the most critical concern is the impact of acquiring the virus during pregnancy. Understanding this mode of transmission is key in public health, especially in developing strategies to prevent congenital infections.

While other modes of transmission such as through body fluids, saliva, or sexual intercourse also play a role in the spread of HCMV in the population, they are not the primary concern when referencing initial infections leading to congenital transmission. Thus, recognizing that transplacental transfer is the primary route for initial infection highlights the unique risks posed during pregnancy.