Cytomegalovirus (CMV)

Categorization
Genome: DNA Virus, dsDNA Virus Structure: Enveloped Virus, Icosahedral Virus
Transmission
  • Cytomegalovirus (CMV) is shed in a variety of bodily fluids and transmission requires close contact. Infection can also cocur transplecentally during mother-to-child transmission and thus CMV is considered a TORCHES Organism. Donor-to-recipient infection following organ transplantation is particularly of concern as transplant recipient are often placed on significant immunosuppressant drugs.
Clinical Consequences
  • Overview
    • CMV can result in a wide variety of clinical consequences depending on the age of transmission and immune status of the patient. Fetal infection with CMV can result in severe birth defects; however, infection after birth is usually subclinical and goes unnoticed. Following primary infection, the virus enters latency and remains in the host for life, potentially reactivating and shedding virus in the body fluids at any time. Because cell-mediated immunity is critical for control, immunocompromised patients can display severe disease.
  • Congenital CMV
    • Fetal infection usually occurs if the mother undergoes primary CMV infection during pregnancy although transmission during reactivation is also possible. Congenital infection results in poor intrauterine growth and increases intrauterine death. Those who survive may be born with microcephaly and suffer from mental retardation or hearing loss in the future.
  • CMV Mononucleosis
    • Although infection with CMV is usually asymptomatic in most individuals after birth, occasionally a mononucleosis can result. Like EBV-mononcleosis, CMV mononucleosis is characterized by the presence of a atypical lymphocytes in the peripheral blood along with some constitutional symptoms together with malaise. In contrast to EBV-mononucleosis, there is no pharyngitis or cervical lymphadenopathy, and heterophile antibodies are absent.
  • Immunocompromised CMV
    • CMV is a frequent cause of disease in immunocompromised patients. In transplant recipients, CMV often causes a severe pneumonia
    • In AIDS Patients, CMV often causes retinitis and a gastroenteritis leading to infectious diarrhea.
Treatment