- Clinical science
Infection with the cytomegalovirus (CMV or human herpes virus 5) is generally asymptomatic in immunocompetent hosts, but can cause mild mononucleosis-like symptoms. Like all Herpesviridae infections, CMV persists for the lifetime of its host; reactivation may therefore occur. Immunocompromised individuals (e.g., AIDS, post-transplantation) are especially at risk of illness following reactivation or initial infection, which can include severe manifestations such as CMV retinitis (risk of blindness) or life-threatening CMV pneumonia. Treatment with ganciclovir or valganciclovir should therefore begin promptly on clinical suspicion of a CMV infection.
is discussed in another learning card.
In immunocompetent patients
- > 90%: asymptomatic course
< 10%: CMV mononucleosis
- Fever, malaise, myalgia/arthralgia, fatigue, headache
- Less common: sore throat, cervical lymphadenopathy, hepatomegaly, splenomegaly
- Differential diagnosis: infectious mononucleosis caused by EBV
In immunocompromised patients
One or more of the following clinical manifestations may be present:
- CMV mononucleosis
CMV pneumonia: interstitial pneumonitis
- Etiology: immunocompromised patients (e.g., following bone marrow transplant or in HIV/AIDS patients with CD4 ≤ 50 cells/mm3)
- Clinical findings: fever, nonproductive cough, dyspnea
- Differential diagnoses: and other viral respiratory infections
- CMV retinitis: floaters, photopsia, visual field defects
- CMV esophagitis: and/or CMV colitis: odynophagia, abdominal pain, bloody diarrhea: Endoscopic examination of the GI tract typically shows linear ulcers.
- CMV encephalitis: impaired cognitive function, neurological deficits
- CBC: relative lymphocytosis with > 10% atypical lymphocytesand sometimes pancytopenia
- Blood smear: : large atypical lymphocytes with intranuclear inclusion bodies that have an owl-eye appearance
- Monospot (heterophile antibody) test: negative
- Serological tests
- Direct evidence of viremia: especially useful in immunosuppressed patients
- Fundoscopy: retinal hemorrhages and cotton-wool spots (“pizza-pie” appearance)
Serological tests may be unreliable in immunosuppressed patients!
- In immunocompetent patients: No specific treatment is needed.
- In immunosuppressed patients
|CMV retinitis|| |
|CMV colitis|| |
|CMV pneumonia|| |
|CMV encephalitis|| |