HHV 4EBV EpsteinBarr Virus EpsteinBarr virus EBV HHV4

HHV 4(EBV)

Epstein-Barr Virus Epstein-Barr virus (EBV) (HHV-4) infects • oropharyngeal B-cell lymphocytes; latency is established locally and in lymphatic tissue throughout the body. Primary • infection mainly occurs when asymptomatic persons shedding EBV in saliva have intimate contact with • previously uninfected persons. Most often, infection is asymptomatic and transpires in children and • adolescents; antibodies to EBV are present in 95% of adults worldwide. EBV is the most common cause of • infectious mononucleosis, characterized by an exudative pharyngitis, fever, and lymphadenopathy (mostly • cervical).

Splenomegaly is present in approximately • 50% of patients. Other, less frequent findings • include jaundice, hepatomegaly, and an erythema multiforme–like rash. In most cases, disease spontaneously • resolve within 2 to 3 weeks; however, subsequent asthenia may persist for variable periods. EBV is • associated with the development of certain malignancies in immunosuppressed and immunocompetent • hosts

Diagnosis can be confirmed by the presence of EBV • heterophile (Monospot) antibodies or by the detection of EBV-specific antibodies, particularly Ig. M, to the EBV • viral capsid antigen. With mononucleosis, a lymphocytosis typically exists, classically consisting of • atypical lymphocytes. Thrombocytopenia, elevated hepatocellular enzymes, lactate dehydrogenase, and • bilirubin are other commonly found laboratory abnormalities. • Acyclovir and other antiviral agents have not proven • beneficial in the treatment of infectious mononucleosis or EBV malignancies. Glucocorticoids should be • reserved for complications of EBV, such as a compromised airway or autoimmune hemolytic anemia but in general • are not recommended for the treatment of mononucleosis. •

Malignancies associated with EBV: 1 -NASOPHARYNGEAL CARCINOMA. • 2 -BURKITT LYMPHOMA. • 3 -CNS lymphoma (in patients with AIDS). • 4 -POSTTRANSPLANT LYMPHOPROLIFERATIVE • DISORDERS. 5 -HAIRY LEUKOPLAKIA • 6 -Hodgkin lymphoma. •

Differential diagnosis of mononucleosis like syndrome: 1 -CMV. • 2 -HIV. • 3 -HHV-6 • 4 -Herpes simplex virus type 1&2. • 5 -Group A beta hemolytic streptococcus pyogenes. • 6 -toxoplasma gondii. • 7 -Hodgkin and non HODGKIN LYMPHOMA. • 8 -Rubella. • 9 -TB adenitis. • 10 -hepatitis A and B VIRUS. •

Human Cytomegalovirus Most cases of cytomegalovirus (CMV) • infection (HHV-5) are asymptomatic, and the virus remains latent afterward. Serologic evidence of CMV is • present in 60% to 100% of adults worldwide. CMV may spread by close contact through saliva, blood • transfusion, organ transplantation, and breastfeeding. Disease acquisition can also occur through congenital • or sexual transmission.

Symptomatic primary infection usually • manifests as a mononucleosis-like syndrome. • Compared with patients who have EBV mononucleosis, patients are usually older and have pharyngitis less • often. Fever alone may predominate, making CMV a consideration in persons with fever of unknown origin. • The lung, liver, heart, and hematologic and central nervous systems may be involved during primary • infection. Latent CMV frequently reactivates in immunocompromised patients. Manifestations of • secondary infection include fever, retinitis, pneumonitis, hepatitis, esophagitis, gastritis, colitis, and • meningoencephalitis.

Diagnosis relies on isolation of the virus from • body fluids, such as urine; detection of CMV pp 65 antigen in leukocytes; cytopathic demonstration of “owl's • eye” intracellular inclusions; PCR; and serologic assays. Antiviral treatment is typically indicated in cases • of disease reactivation in immunocompromised patients and occasionally in immunocompetent hosts with severe disease, Ganciclovir and valganciclovir are first line agents and can be used as prophylaxis in certain transplant patients. Fascarnet and cidofovir are second line agents.