Epstein-Barr Virus (EBV) & Infectious Mononucleosis

Key Features

Essentials of Diagnosis

• Malaise, fever, and (exudative) sore throat

• Palatal petechiae, lymphadenopathy, splenomegaly, and, occasionally, a maculopapular rash

• Positive heterophile agglutination test (Monospot)

• Atypical large lymphocytes in blood smear; lymphocytosis

• Complications: hepatitis, myocarditis, neuropathy, encephalitis, airway obstruction from adenitis, hemolytic anemia, thrombocytopenia

General Considerations

• EBV is ubiquitous; infects > 95% of the adult population worldwide and persists for the person's lifetime

• Infectious mononucleosis is a common manifestation of EBV and may occur at any age

• EBV is largely transmitted by saliva but can also be recovered from genital secretions

• Saliva may remain infectious during convalescence, for 6 months or longer after symptom onset

• The incubation period lasts several weeks (30–50 days)

• In the United States the incidence of EBV infection is declining although prevalence of EBV remains high for those aged 12–19 years

Clinical Findings

Symptoms and Signs

• Fever, sore throat, fatigue, malaise, anorexia, and myalgia typically occur in the early phase of the illness

• Physical findings include

  • Lymphadenopathy (discrete, nonsuppurative, slightly painful, especially along the posterior cervical chain)

  • Transient bilateral upper lid edema (Hoagland sign)

  • Splenomegaly (in up to 50% of patients and sometimes massive)

• Conjunctival hemorrhage, exudative pharyngitis, uvular edema, tonsillitis, or gingivitis may occur

• Soft palatal petechiae may be noted

• Other manifestations

  • Hepatitis

  • Interstitial pneumonitis (sometimes with pleural involvement)

  • Cholestasis

  • Gastritis

  • Kidney disease (mostly interstitial nephritis)

  • Epiglottitis

  • Nervous system involvement (in 1–5%)

Differential Diagnosis

• Cytomegalovirus infection

• Toxoplasmosis

• Acute HIV infection

• Secondary syphilis

• HHV-6 infection

• Rubella

• Drug hypersensitivity reactions

Diagnosis

• Diagnosis is made based on characteristic manifestations and serologic evidence of infection (the heterophile sheep cell agglutination [HA] antibody tests or the correlated mononucleosis spot test [Monospot])

• Polymerase chain reaction (PCR) for EBV DNA is useful in the evaluation of malignancies associated with EBV

Treatment

• No specific antiviral therapy is needed in more than 95% of patients with acute EBV-associated infectious mononucleosis

• NSAIDs or acetaminophen and warm saline throat irrigations or gargles three or four times daily can manage symptoms

• If a throat culture grows β-hemolytic streptococci, a 10-day course of penicillin or azithromycin is indicated

• Corticosteroid therapy is reserved for impending airway obstruction from enlarged lymph nodes, hemolytic anemia, and severe thrombocytopenia

Outcome

Complications

• Secondary bacterial pharyngitis can occur and is often streptococcal

• Splenic rupture (0.5–1%) is a rare but dramatic complication, and a history of preceding trauma can be elicited in 50% of the cases

• Calculous cholecystitis, acute liver failure with massive necrosis, pericarditis and myocarditis are also infrequent complications

Prevention

• Hand washing after ...