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L6
HHV 4 (EBV)
D. Haider
HHV 4(EBV)
Epstein - Barr virus
Epstein-Barr virus (EBV) (HHV-5) 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 IgM, 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.
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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 pp65
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.
Mubark A. Wilkins