Epidemiology


Etiology


Pathophysiology


Clinical features


  • Immunocompetent Pts
    • Often asymptomatic or presents as a mononucleosis-like syndrome.
    • Symptoms include fever, malaise, myalgias, and atypical lymphocytosis.
    • A key distinguishing feature from EBV mononucleosis is the negative heterophile antibody (Monospot) test. Pharyngitis and significant lymphadenopathy are less common than in EBV.
  • Immunocompromised Pts (e.g., HIV/AIDS, Transplant Recipients)
    • At high risk for severe, end-organ disease, particularly when the CD4+ count is <50 cells/µL in AIDS patients.
    • Retinitis: The most common manifestation in advanced AIDS, presenting with hemorrhage and cotton-wool exudates on fundoscopy (“pizza pie” or “ketchup and mustard” appearance). Can lead to retinal detachment and blindness.
    • Colitis: Results in diarrhea, fever, and abdominal pain. Endoscopy often reveals ulcerations. c
    • Esophagitis: Causes odynophagia (painful swallowing). Endoscopy typically shows large, linear ulcers in the distal esophagus.
    • Pneumonitis: A significant cause of morbidity and mortality in transplant recipients, especially after lung or hematopoietic stem cell transplants.
    • Encephalitis: Can occur in severely immunocompromised patients.
  • Congenital CMV
    • The most common congenital viral infection.
    • ~90% of infected newborns are asymptomatic at birth.
    • Symptomatic newborns may present with hepatosplenomegaly, jaundice, thrombocytopenic purpura (“blueberry muffin” rash), microcephaly, and periventricular calcifications.
    • CMV is a leading cause of non-hereditary sensorineural hearing loss in children.

Diagnostics


  • Initial / Screening Tests:
    • Immunocompetent: Monospot test = Negative; peripheral smear shows atypical lymphocytes.
    • Immunocompromised: CMV Quantitative PCR (plasma/blood) or viral load monitoring.
    • Congenital: CMV PCR in urine or saliva within first 2–3 weeks of life.
  • Confirmatory / Gold Standard Tests:
    • Tissue-invasive disease (GI/Lung): Endoscopy/Tissue Biopsy showing “Owl’s eye” inclusion bodies (large cells with basophilic intranuclear & intracytoplasmic inclusions).
    • CMV Retinitis: Clinical fundoscopic diagnosis showing “Pizza-pie” / “Egg-and-ketchup” appearance (retinal hemorrhages w/ yellow-white exudates).
  • Key Imaging:
    • Brain CT/MRI (Congenital): Periventricular calcifications.
    • Endoscopy (GI): Linear, shallow mucosal ulcerations in esophagus or colon.

Treatment


  • Preferred: ganciclovir or valganciclovir
  • Alternatives: foscarnet, cidofovir