Cytomegalovirus Disease

Cytomegalovirus disease is caused by infection with a herpesvirus belonging to the genus Cytomegalovirus.

In humans, the virus can spread through infected body fluids, such as during blood transfusion, organ transplant, sexual contact, or from mother to fetus.

Once inside the body, the virus establishes latency primarily in monocytes and hematopoietic progenitor cells.

During active infection, it interferes with MHC class I antigen presentation, preventing CD8⁺ T cells from recognizing and eliminating infected cells.

Some viral proteins attach to host chemokines, hindering the recruitment of immune cells to the infection site.

Together, these mechanisms allow the virus to persist within host cells.

When a person's immunity is weakened, such as after an organ transplant, the virus may become active again.

It takes over the host cell to produce and release new virions, spreading the infection.

Virus-infected cells, especially in epithelial tissues, become enlarged and develop characteristic intranuclear inclusion bodies, which are visible under a microscope.