cytomegalovirus (CMV)

see also:

• viruses
• EBV / glandular fever / infectious mononucleosis

• CMV is a member of the Herpesviridae family
• ~60% of western populations have been infected with CMV, most are asymptomatic, but it may become reactivated if T-cell immunity falls
• appears to be the cause of glioblastoma multiforme ¹⁾
  • CMV proteins are highly expressed in over 90% of GBM tumors

• CMV is the major infectious cause of congenital malformations
• an Australian study²⁾ covering 1999-2023 showed:
  • 586 cases of congenital CMV infection were reported (~8 per 100,000 births) BUT this is only 1% of the number expected in Australia on the basis of their estimated prevalence in developed countries indicating need for greater surveillance and reporting as infants are not routinely screened for congenital CMV infections
  • most frequent sequelae of definite infections were:
    • small for gestational age or intrauterine growth restriction (135 infants, 28.2%);
    • neurological conditions (most frequently: deafness [183, 38.2%], microcephaly [89, 18.6%]);
    • liver disease with jaundice (130, 27.1%), hepatomegaly (75, 15.7%), or hepatitis (85, 14.7%);
    • bone marrow conditions (most frequently: thrombocytopaenia [139, 29.0%], petechiae/purpura [89, 18.6%]).

• if symptomatic, incubation period is 9-60 days
• may cause:
  • a flu-like illness with pharyngitis, perhaps mild pneumonitis with fine crackles
  • PUO
  • lymphadenopathy
  • splenomegaly

• may result in a mononucleosis syndrome and affect most organs in the body:
  • PUO
  • pneumonitis
  • hepatitis
  • encephalitis
  • myelitis
  • colitis
  • uveitis
  • retinitis
  • neuropathy
  • rarely:
    • Guillain-Barre syndrome (GBS)
    • pericarditis
    • myocarditis
    • thrombocytopenia
    • haemolytic anaemia

• CMV normally remains dormant but may become reactivated if T-lymphocyte mediated immunity becomes compromised as in:
  • AIDS
  • immunosuppressants such as azathioprine Rx
• CMV viraemia may then lead to:
  • severe pneumonitis
  • secondary haemophagocytic syndrome
• if CMV reactivation occurs during breastfeeding:
  • the ensuing immune response may affect milk composition, neonatal gut flora with lower levels of beneficial flora, and impaired development of gut microbiome and impaired infant growth. ³⁾