12- Epstein Barr virus (EBV).ppt all information available

eBarr virus

1. Present by : Rakholiya Deep Group: 20/19 Epstein Barr virus (EBV)

2. Epstein Barr virus (EBV) Family: Hrepesviridae. Subfamily: Gamma herpesvirinae. Enveloped. Icosahedral nucleocapsid. The viral genome is ds-DNA. Replicate in the nucleus. Remain latent in B- cells.

3. Pathophysiology of EBV infection EBV is transmitted via intimate contact with body secretions, primarily oropharyngeal secretions. EBV infects the B cells in the oropharyngeal epithelium. On rare occasion, EBV is spread via blood transfusion. Circulating B cells spread the infection throughout the entire reticular endothelial system (RES), ie, liver, spleen, and peripheral lymph nodes. EBV infection of B lymphocytes results in a humoral and cellular response to the virus. The humoral immune response directed against EBV structural proteins. the T-lymphocyte response is essential in the control of EBV infection; natural killer (NK) cells and predominantly CD8+ cytotoxic T cells control proliferating B lymphocytes infected with EBV The T-lymphocyte cellular response is critical in determining the clinical expression of EBV viral infection. A rapid and efficient T-cell response results in control of the primary EBV infection and lifelong suppression of EBV. Ineffective T-cell response may result in excessive and uncontrolled B-cell proliferation, resulting in B-lymphocyte malignancies The immune response to EBV infection is fever, which occurs because of cytokine release consequent to B-lymphocyte invasion by EBV.

4. Clinical syndromes associated with EBV infection Infectious mononucleosis. Chronic EBV infection. Lymphoproliferative disorder in immunocompromised. Burkitt lymphoma. Nasopharyngeal carcinoma.

5. Infectious mononucleosis Transmitted by direct contact with saliva. The virus is shed in saliva. Target group : adolescents . IP : 4-7 weeks.

6. Signs and symptoms Children infected with EBV develops no symptoms. When infection occurs in adolescence , it causes infectious mono nucleosis. The main symptoms are: Fever, sore throat, generalized lymphadenopathy, malaise, fatigue, hepatosplenomegaly, abnormal LFT. The most important characteristics of infectious mononucleosis are the development of heterophil antibody to sheep red blood cell and lymphocytosis with atypical lymphocytes.

7. Infectious mononucleosis

8. Lymphocytosis with atypical lymphocytes .

9. Prognosis and duration Self limiting disease, but the virus remain latent in B-cells. The disease seldom lasts for more than 4-montghs.

10. Lab diagnosis Recent infection: by detection of Ig-M antibody to the viral capsid antigen (VCA). Immunity: When Ig-G antibodies to both viral capsid antigen (VCA) and nuclear antigen(EBNA) are present.

11. C omplications and Prognosis Complications: Menigoencephalitis, thrombocytopenia, carditis, Guillain-Barr syndrome Infectious monnucleolosis is self limiting disease, after recovery , the virus remain latent in B- cells.

12. T reatment There is no specific anti viral drug therapy, treatment is supportive. Only symptomatic and/or supportive treatments are used. Rest during the acute phase of the infection, but activity should be resumed once acute symptoms have resolved. Heavy physical activity and contact sports should be avoided (risk of splenic rupture ) for at least one month following initial infection and until splenomegaly has resolved, as determined by ultrasound scan. Paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs) ( to reduce fever and pain ). Intravenous corticosteroids ( hydrocortisone or dexamethasone ), useful if there is a risk of airway obstruction, severe thrombocytopenia, or hemolytic anemia .

13. Buirkitt lymphoma(BL) There are three main types of Buirkitt lymphoma: endemic , Sporadic and immunodeficiency-related. The endemic form of the disease is very common in Africa, where EBV and malaria are endemic. The sporadic form occurs throughout the world. The immunodeficiency is most often seen in AIDS patients. BL is an aggressive B-cell non-Hodgkin lymphoma, it may affects the jaw, CNS, kidneys, bowl and ovaries in adults.

14. BL The African form of BL most often present with swelling of the affected jaw or other facial bones, loosing teeth, swelling of the lymph nodes, whish are tender and rapidly growing in the neck below the jaw. Patients with the sporadic form of BL most commonly present with abdominal tumors, causing swelling and pain in the affected area. It may affects the CNs, kidneys, ovaries and other organs.

15. BL

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