2 CMV & EBV Outline Structure Classification Multiplication Clinical manifestationsEpidemiologyDiagnosisControlBaron’s Web Site
3 Latent InfectionsALL herpes viruses can establish latent infections. The viral genome may become incorporated into the host DNA or remain extrachromosomalLatent viruses can be reactivated by stress, menstruation or uv lightReactivation may be asymptomatic or lead to mild or severe disease.
4 Herpes Diagnosis Isolation of virus by tissue culture herpevirinae cause cytopathic effectsintranuclear fluorescence of scrapings using fluorescent antibodiesPCR being developedCMV retiniitis is diagnosed clinically
6 Epstein-Barr virusvirus established in lymphoid tissue and salivary glands - is excreted from salivary glands.Epstein-Barr virus is a transforming DNA virus.
7 EBV Historyinfectious mononucleosis, first described more than 100 years ago.in 1958, Michael Burkitt discovered that a malignant tumour, Burkitt’s lymphoma, was infectious.in 1959, Michael Epstein and Yvonne Barr cultured a virus from tumours that showed typical herpes-like morphology.
8 EBV and Burkitt’s lymphoma were shown to be the same virus when a lab technician acquired mononucleosis while working with the Burkitt’s lymphoma virus.
9 EBV Diseases Infectious mononucleosis lymphoproliferative cancer in heart and bone marrow transplant recipientsBurkitt’s lymphoma (B cell carcinoma) in E. africansnasopharyngeal carcinoma in Chinese
10 Classic Mononucleosis infectious mononucleosis has an incubation period of 30 to 50 days.high fever, malaise, myalgia, cervical lymphadenopathy, splenomegaly, hepatomegalyhigh fever, pharyngitis, grey-white pharyngeal exudate, skin rashatypical lymphocytosis or leucocytosis: infected B cells, T cells (suppresser and cytotoxic)recover due to a strong cell-mediated response
11 Complications Carcinoma Burkitt’s lymphoma (B cell carcinoma)Nasopharyngeal carcinoma.if there is an immune deficiency especially of T cells - the host is highly susceptible to Epstein-Barr virus.
12 Infectious Mononucleosis Diagnosis clinical symptomsdifferential blood count - lymphocytosis, neutropenia, large atypical cells.heterophile antibodiesantibodies to EBV nuclear antigenantibodies to EBV capsid antigen
13 Infectious Mononucleosis Transmission direct oral contactexposure to salivafomitesarthropod vectors
14 Exposure early in Africa and Asia, later in industrialized countries 70% of college age persons have never had exposure - very susceptible to the virus.95% of middle aged adults are seropositive.
15 Portal of Entry oropharynx attaches to the epithelium moves to the Parotid glandviremialatent in throat and bloodsubclinical asymptomatic
16 Epstein-Barr Virus - Symptoms sore throat, high fever, cervical lymphadenopathy, grey-white pharyngeal exudate, skin rash, enlarged liver and spleen.Leucocytosis: infected B cells, T cells (suppresser and cytotoxic)recover due to a strong cell-mediated response (T cell).
17 Cancer Transformation of the cell by virus Helper virus if the transforming virus is defectiveCo-carcinogen, chemical, cigarette smoke
18 Transformed cells: Not warts: Papovavirus lose contact inhibition continue to divideform random aggregationscan become invasiveNot warts: Papovavirus
19 Primary Hepatocellular Carcinoma Icteric symptoms:jaundice, dark urine, pale stoolsHighest incidence:Central AfricaSoutheast ChinaPacific Islands, Borneo, Sarawak, Taiwan250,000 to1,000,000 deaths worldwide per yearU.S.A deaths / year
20 Human T-cell Leukemia Virus HTLV1 & HTLV2retroviruses with no oncogenesAdult T-cell leukemia and lymphoma - Southern Japan, Carribean Islands, West Africa
21 Epstein Barr Southern China, Asia suspect co-carcinogen: - nitrosamines in salted fishoncogenes not reported.
22 Burkitts Lymphoma East Africa, Papua New Guinea at risk: year old malestumor of immature B-cells
23 Human Papillomavirus cervical, penile, vulval, and rectal cancer viral genome integrated into host genomeCo-carcinogens - cigarette smoke - HSV herpes
28 Transmission: CMVnot highly infectious, virus found in saliva, urine and blood.infants and children acquire CMV from other children.congenital. In utero, at birth during perinatal period.
29 Congenital: CMVthe following possibilities relate to the congenital type.severe deformities and death.survive with serious defects - physical and mental.survive with out deformities.newborns: - Enlarged liver and spleen, jaundice, capillary bleeding, microcephaly, ocular inflammation.
30 Disseminated cytomegalovirus fever, severe diarrhea, hepatitis, arthritis, pneumonia, high mortality.activation of inapparent infection.also due to:immunosuppressive therapy.cancer.AIDS.
31 Virus in blood or organ: post transfusion.post organ transplant.
32 Cytomegalovirus mononucleosis: teenage, young adult similar to other mono.
34 Differential Diagnosis: the differential diagnosis in neonates must include toxoplasmosis, rubella, herpes simplex, bacterial sepsis.in adults it must be differentiated from Epstein-Barra and hepatitis A & B.
35 Laboratory diagnosis: CMV virus can be grown from all organs.many serological tests.
36 Treatment: CMVgancyclovir, foscarnet, hyperimmune CMV immunoglobulin, have some effect.interferon does not prevent infection or promote recovery.
37 Prevention:CMV no animal can be found that can be infected with CMV. Two deterents:vaccine stimulated antibodies may not be protective. Patients already seropositve can be reinfected.a vaccine could be oncogenic.
38 Epidemiology of CMV 40-100% positive for the antibodies. newborns 7.5% positive in the USA & UK.woman of child bearing age were % positive in many countries that were studied (pregnant - virus in the urine).IV drug users were 100% positive for the antibodies.homosexual males were 30% positive for the antibodies - high percentage shed virus.