The Epstein-Barr virus (EBV) is a DNA virus that infects over 90% of people, primarily through oral secretions, with infectious mononucleosis often referred to as the 'kissing disease.' Clinical manifestations vary by age, presenting as mild infections in children and more severe symptoms in adolescents and adults, particularly in immunocompromised patients who may develop EBV-related malignancies. Diagnosis is primarily through serologic testing, and treatment focuses on supportive care, with potential interventions for specific complications.

1. EBSTEIN-BARR VIRUS

2. Introduction
• Epidemiology EBV is a DNA virus in the family Herpesviridae that infects >90% of
persons by adulthood.
• EBV is spread by contact with oral secretions (e.g., by transfer of saliva during
kissing) and is shed in oropharyngeal secretions by >90% of asymptomatic
seropositive individuals.
• Infectious Mononucleosis is also called “kissing disease”.

3. Pathogenesis
• EBV infects the epithelium of the oropharynx and salivary glands as well as B cells
in tonsillar crypts prior to a period of viremia.
• There is polyclonal activation of B cells, and memory B cells form the reservoir
for EBV.
• Cellular immunity is more important than humoral immunity in controlling
infection. If T cell immunity is compromised, EBV-infected B cells may
proliferate—a step toward neoplastic transformation.

4. Clinical Manifestations
• Young children typically develop asymptomatic infections or mild pharyngitis,
adolescents and adults develop an infectious mononucleosis (IM) syndrome, and
immunocompromised pts can develop lymphoproliferative disease.
• Infectious Mononucleosis : fatigue, malaise, and myalgia may last for 1–2 weeks before
the onset of fever, exudative pharyngitis, and lymphadenopathy with tender,
symmetric, and movable nodes; splenomegaly is more prominent in the second or third
week. Lymphocytosis occurs in the second or third week, with >10% atypical
lymphocytes (enlarged cells with abundant cytoplasm and vacuoles); abnormal liver
function is common.
• Lymphoproliferative disease—i.e., infiltration of lymph nodes and multiple organs by
proliferating EBV-infected B cells—occurs in pts with deficient cellular immunity
• EBV-associated malignancies include Burkitt’s lymphoma, anaplastic nasopharyngeal
carcinoma, Hodgkin’s disease, Oral hairy leukoplakia.

5. Complications
• CNS disease (e.g., meningitis, encephalitis),
• Coombs-positive autoimmune hemolytic anemia,
• splenic rupture, and
• upper airway obstruction due to hypertrophy of lymphoid tissue

6. Investigation
• Serologic testing is the mainstay of diagnostic assessment.
• PCR analysis can be useful in monitoring EBV DNA levels in blood
• Heterophile antibodies form the basis of most rapid testing, The antibodies can persist
for up to 1 year after infection.
• EBV-specific antibody testing can be used in heterophilenegative pts and pts with
atypical disease
• Antibodies to Epstein-Barr nuclear antigen are not detected until 3–6 weeks after
symptom onset and then persist for life.

7. Treatment
• Supportive measures, including rest and analgesia. – Excessive physical activity should be
avoided in the first month of illness to reduce the possibility of splenic rupture, which
necessitates splenectomy.
• Administration of glucocorticoids may be indicated for some complications of IM
• Antiviral therapy (e.g., with acyclovir) is generally not effective for IM but is effective for
oral hairy leukoplakia.
• EBV lymphoproliferative syndrome is generally directed toward reduction of
immunosuppression e.g., with interferon α, antibody to CD20 (rituximab), and donor
lymphocyte infusions.