What is the clinical presentation of acute cytomegalovirus (CMV) infection in adults?

Clinical Presentation of Acute Cytomegalovirus (CMV) Infection in Adults

Acute CMV infection in immunocompetent adults typically presents as a prolonged fever of unknown origin (lasting 3-8 weeks) with intense asthenia, lymphomonocytosis, and mild-to-moderate transaminase elevation, while immunocompromised patients most commonly develop CMV retinitis followed by colitis, with symptoms varying by the affected organ system.

Immunocompetent Adults

Primary Symptoms

The clinical picture in previously healthy adults is characterized by:

• Fever: Present in 85% of cases, lasting 3-50 days (often 3-8 weeks) 1, 2, 3, 4
• Intense asthenia/fatigue: Occurs in 83% of patients and can persist for weeks 1, 2, 5
• Absence of pharyngitis: This distinguishes CMV from Epstein-Barr virus infection 2, 4

Laboratory Findings

• Lymphomonocytosis: Present in 100% of cases, with atypical lymphocytes appearing 2-3 weeks after fever onset 1, 2, 4
• Transaminase elevation: Moderate increase (ALT elevated 6-fold, AST 3.5-fold on average), typically 2-5 times normal, rarely exceeding 5 μmol/s/L 2, 3, 4
• Absence of jaundice: Helps differentiate from acute viral hepatitis A or B 2

Additional Clinical Features (Present in 20-30% of Cases)

• Hepatomegaly (19-30%) without jaundice 1, 2, 4
• Splenomegaly (20-30%) 1, 2, 4
• Lymphadenopathy (22%) - less frequent than in EBV 1, 2
• Headache (25%) 2
• Myalgias (25%) 2
• Morbilliform or petechial rash (30-50%) 4
• Upper respiratory tract symptoms 1
• Community-acquired pneumonia (less common) 1

Rare Severe Complications in Immunocompetent Hosts

• Splanchnic vein thrombosis (portal vein, superior mesenteric vein) with splenic infarction 6
• Hyperinflammatory states mimicking hemophagocytic lymphohistiocytosis or adult-onset Still's disease 7

Important caveat: The diagnosis is frequently missed initially, with an 85.3% rate of incorrect preliminary diagnoses, due to the absence of pathognomonic symptoms 1.

Immunocompromised Patients

Risk Factors

CMV end-organ disease occurs primarily in patients with:

• CD4+ T-cell counts <50 cells/µL 8, 9
• Post-transplant recipients (allogeneic HSCT, solid organ transplant) 10, 11, 12
• HIV/AIDS patients 8, 9
• Patients on immunosuppressive therapy 10, 12
• High plasma HIV-1 RNA levels (>100,000 copies/mL) 9

Clinical Manifestations by Organ System

CMV Retinitis (Most Common End-Organ Disease)

• Presentation: Initially unilateral in two-thirds of patients, but progresses to bilateral without treatment 8, 9
• Peripheral lesions: Asymptomatic or present with floaters, scotomata, peripheral visual field defects 8, 9, 8
• Central lesions: Decreased visual acuity, central field defects when involving macula or optic nerve 8, 9, 8
• Ophthalmologic appearance: Fluffy yellow-white retinal lesions (full-thickness necrotizing retinitis), with or without intraretinal hemorrhage, minimal vitreous inflammation, blood vessel sheathing 8, 9, 8, 9
• Progression pattern: "Brushfire" pattern with granular white leading edge advancing before atrophic gliotic scar, progressing within 10-21 days without treatment 8, 9, 8

CMV Colitis (5-10% of CMV End-Organ Disease)

• Symptoms: Fever, weight loss, anorexia, abdominal pain, debilitating diarrhea, malaise 8, 9, 8, 9
• Life-threatening complications: Extensive mucosal hemorrhage, perforation, toxic megacolon, fulminant colitis, ischemia 10, 8, 9
• Mortality: In-hospital mortality approaches 70% in severely ill patients despite treatment; up to 7 times higher mortality in patients with concurrent inflammatory bowel disease 10
• Endoscopic findings: Well-defined, punched-out ulcerations in up to 80% of patients; typical cecum ulcer involving ileocecal valve in graft-versus-host disease patients 10
• Imaging: Bowel wall thickening (almost always present), small bowel involvement in 40% (helps differentiate from C. difficile colitis) 10

Critical point: Patients with CMV colitis typically do NOT present with classical CMV viremia symptoms (pharyngitis, lymphadenopathy, splenomegaly) 10.

CMV Esophagitis (<5-10% of CMV End-Organ Disease)

• Fever, odynophagia, nausea, mid-epigastric or retrosternal discomfort 8, 9, 8, 9
• Extensive large, shallow ulcers of distal esophagus on endoscopy 8

CMV Pneumonitis (Uncommon)

• Shortness of breath, dyspnea on exertion, nonproductive cough, hypoxemia 9
• Interstitial infiltrates on chest radiograph 9
• Progressive interstitial pneumonitis can lead to respiratory failure 12

CMV Neurologic Disease

CMV Dementia:

• Lethargy, confusion, fever (mimics HIV dementia) 8, 9, 8, 9
• CSF: Lymphocytic pleocytosis (or mixed neutrophils/lymphocytes), low-to-normal glucose, normal-to-elevated protein 8, 9, 8

CMV Ventriculoencephalitis:

• Acute course with focal neurologic signs, cranial nerve palsies, nystagmus 8, 9, 8, 9
• Rapid progression to death 8, 9, 8
• Periventricular enhancement on CT/MRI (distinguishes from HIV-related disease) 8, 9, 8

CMV Polyradiculomyelopathy:

• Guillain-Barré-like syndrome: urinary retention, progressive bilateral leg weakness 8, 9, 8, 9
• Progression over several weeks to loss of bowel/bladder control and flaccid paraplegia 8, 9, 8
• Sacral paresthesia may occur 8, 9, 8
• CSF: Neutrophilic pleocytosis (100-200 neutrophils/µL with erythrocytes), hypoglycorrhachia, elevated protein 8, 9, 8

Diagnostic Approach

Immunocompetent Adults

• Serologic testing: IgM anti-CMV antibodies confirm acute infection 1, 2, 5, 3
• Molecular testing: CMV PCR in blood and urine 1
• Consider CMV when: Prolonged fever + lymphomonocytosis + mild transaminase elevation + absence of pharyngitis 1, 2

Immunocompromised Patients

• CMV viremia: Detected by PCR or antigen assays; present in end-organ disease but can occur without disease 8, 9, 8, 13
• Serology: NOT diagnostically useful in immunocompromised patients; negative IgG suggests CMV unlikely (but seroreversion can occur) 8, 9, 8
• Retinitis: Clinical diagnosis by experienced ophthalmologist (95% positive predictive value); rarely requires vitreous PCR 8
• Colitis/Esophagitis: Endoscopy with biopsy showing "owl eye" intranuclear inclusions; CMV-specific immunohistochemistry is gold standard 10, 8
• Neurologic disease: Compatible clinical syndrome + CMV in CSF by PCR 9

Critical diagnostic pitfall: Blood serology has NO diagnostic value in diagnosing CMV colitis in immunocompromised patients, as CMV seroprevalence is ≥70% in adults 10.