Cytomegalovirus (CMV) infection
Cytomegalovirus is a ubiquitous herpesvirus that is usually asymptomatic or causes a heterophile-negative mononucleosis-like illness in healthy hosts, but reactivates to cause retinitis, colitis, pneumonitis, or encephalitis in transplant recipients and patients with AIDS; treatment is systemic ganciclovir or valganciclovir, with foscarnet and cidofovir reserved for resistance or intolerance.
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What this article covers
- Overview
A ubiquitous herpesvirus (HHV-5) that establishes lifelong latency: 60% to 90% of adults are latently infected, and disease results from primary infection or reactivation, most often with impaired cell-mediated immunity.
- Epidemiology
60% to 90% of adults carry latent CMV infection, with prevalence rising with age and varying by region and socioeconomic status.
- Risk factors
CD4 count under 50/microliter in HIV infection: the dominant threshold for serious end-organ CMV disease.
- Pathophysiology
Primary infection or reactivation of latent virus in monocytes, lymphocytes, and endothelial/epithelial cells allows hematogenous CMV dissemination to multiple organs.
- Clinical features
In immunocompetent hosts, most infection is asymptomatic; when symptomatic, it produces a mononucleosis-like syndrome with fever and malaise but without pharyngitis, and with a negative heterophile antibody (Monospot) test.
- Differential diagnosis
Infectious mononucleosis (Epstein-Barr virus): exudative pharyngitis, posterior cervical lymphadenopathy, splenomegaly, and a positive heterophile antibody test, in contrast to the pharyngitis-free…
- Diagnosis
CMV disease is confirmed by demonstrating the virus in the relevant fluid or tissue: quantitative nucleic acid amplification (PCR) of blood, bronchoalveolar lavage fluid, cerebrospinal fluid, or…
- Management
First, distinguish CMV viremia or a nonspecific viral syndrome from confirmed end-organ disease, since the treatment threshold and intensity differ between pre-emptive/prophylactic strategies and treating overt organ disease.
- Complications
Vision loss from CMV retinitis, the most common and most disabling complication of AIDS-associated CMV disease if untreated or diagnosed late.
- Prognosis
Immunocompetent primary infection and reactivation are generally self-limited and carry an excellent prognosis.
- Prevention
High-risk solid organ transplant recipients (donor-positive/recipient-negative, lymphocyte-depleting agents, lung transplant) receive primary valganciclovir prophylaxis for 3-6 months.
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