CMV is the most common viral pathogen complicating organ transplantation, with the greatest risk of infection 1-4 months after transplantation. HIV-infected pts with CD4+ T cell counts of <50-100/µL also are at risk for severe CMV disease.

• Primary CMV infection (including reinfection with a new, donor-derived strain) is more likely than reactivation to cause severe disease with high viral loads.
  • - Reactivation infection is common but less important clinically.
  • - The transplanted organ is at particular risk; e.g., CMV pneumonitis tends to follow lung transplantation.
  • - The risk of severe disease is reduced by antiviral prophylaxis or preemptive therapy.
• Pts present initially with prolonged fever, malaise, anorexia, fatigue, night sweats, and arthralgias or myalgias but can ultimately have multiorgan involvement.
  • - Respiratory involvement is evidenced by tachypnea, hypoxia, unproductive cough, and chest radiographs demonstrating bilateral interstitial or reticulonodular infiltrates.
  • - GI involvement often includes hepatitis and ulcer formation. Colitis is the most common manifestation in organ transplant recipients.
  • - CMV encephalitis, particularly in HIV-infected pts, can occur as either progressive dementia or ventriculoencephalitis characterized by cranial nerve deficits, disorientation, and lethargy.
  • - CMV retinitis is an important cause of blindness in pts with advanced AIDS.