Herpes Viruses EpsteinBarr virus Cytomegalovirus 1 1022020 CMV
Herpes Viruses Epstein-Barr virus Cytomegalovirus 1 10/2/2020
CMV & EBV Outline þStructure þClassification þMultiplication þClinical manifestations þEpidemiology þDiagnosis þControl 2 Baron’s Web Site 10/2/2020
Latent Infections þ ALL herpes viruses can establish latent infections. The viral genome may become incorporated into the host DNA or remain extrachromosomal þLatent viruses can be reactivated by stress, menstruation or uv light þReactivation may be asymptomatic or lead to mild or severe disease. 3 10/2/2020
Herpes Diagnosis þIsolation of virus by tissue culture a herpevirinae cause cytopathic effects þintranuclear fluorescence of scrapings using fluorescent antibodies þPCR being developed CMV retiniitis is diagnosed clinically 4 10/2/2020
Epstein Barr Virus 5 10/2/2020
Epstein-Barr virus þvirus established in lymphoid tissue and salivary glands - is excreted from salivary glands. þEpstein-Barr virus is a transforming DNA virus. 6 10/2/2020
EBV History þinfectious mononucleosis, first described more than 100 years ago. þin 1958, Michael Burkitt discovered that a malignant tumour, Burkitt’s lymphoma, was infectious. 7 þin 1959, Michael Epstein and Yvonne Barr cultured a virus from tumours that showed typical herpes-like morphology. 10/2/2020
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. 8 10/2/2020
EBV Diseases þInfectious mononucleosis þlymphoproliferative cancer in heart and bone marrow transplant recipients þBurkitt’s lymphoma (B cell carcinoma) in E. africans þnasopharyngeal carcinoma in Chinese 9 10/2/2020
Classic Mononucleosis þinfectious mononucleosis has an incubation period of 30 to 50 days. þhigh fever, malaise, myalgia, cervical lymphadenopathy, splenomegaly, hepatomegaly þ high fever, pharyngitis, grey-white pharyngeal exudate, skin rash þatypical lymphocytosis or leucocytosis: infected B cells, T cells (suppresser and cytotoxic) þrecover due to a strong cell-mediated response 10 10/2/2020
Complications þCarcinoma ä Burkitt’s lymphoma (B cell carcinoma) ä Nasopharyngeal carcinoma. þif there is an immune deficiency especially of T cells - the host is highly susceptible to Epstein-Barr virus. 11 10/2/2020
Infectious Mononucleosis Diagnosis þclinical symptoms þdifferential blood count - lymphocytosis, neutropenia, large atypical cells. þheterophile antibodies þantibodies to EBV nuclear antigen þantibodies to EBV capsid antigen 12 10/2/2020
Infectious Mononucleosis Transmission þdirect oral contact þexposure to saliva þfomites þarthropod vectors 13 10/2/2020
Exposure þearly in Africa and Asia, later in industrialized countries þ 70% of college age persons have never had exposure - very susceptible to the virus. þ 95% of middle aged adults are seropositive. 14 10/2/2020
Portal of Entry þoropharynx þattaches to the epithelium þmoves to the Parotid gland þviremia þlatent in throat and blood ä subclinical asymptomatic 15 10/2/2020
Epstein-Barr Virus - Symptoms þsore throat, high fever, cervical lymphadenopathy, grey-white pharyngeal exudate, skin rash, enlarged liver and spleen. þLeucocytosis: infected B cells, T cells (suppresser and cytotoxic) þrecover due to a strong cell-mediated response (T cell). 16 10/2/2020
Cancer þ Transformation of the cell by virus þ Helper virus if the transforming virus is defective þ Co-carcinogen, chemical, cigarette smoke 17 10/2/2020
Transformed cells: ä lose contact inhibition ä continue to divide ä form random aggregations ä can become invasive þNot warts: Papovavirus 18 10/2/2020
Primary Hepatocellular Carcinoma þIcteric symptoms: ä jaundice, dark urine, pale stools þHighest incidence: ä Central Africa ä Southeast China ä Pacific Islands, Borneo, Sarawak, Taiwan 19 þ 250, 000 to 1, 000 deaths worldwide per year þU. S. A. 5000 deaths / year 10/2/2020
Human T-cell Leukemia Virus þHTLV 1 & HTLV 2 þretroviruses with no oncogenes þAdult T-cell leukemia and lymphoma - Southern Japan, Carribean Islands, West Africa 20 10/2/2020
Epstein Barr þSouthern China, Asia þsuspect co-carcinogen: - nitrosamines in salted fish þoncogenes not reported. 21 10/2/2020
Burkitts Lymphoma þ East Africa, Papua New Guinea þ at risk: 6 -14 year old males þ tumor of immature B-cells 22 10/2/2020
Human Papillomavirus þcervical, penile, vulval, and rectal cancer þviral genome integrated into host genome þCo-carcinogens - cigarette smoke - HSV herpes 23 10/2/2020
Cytomegalovirus 24 10/2/2020
Cytomegalovirus þUrine isolate 25 10/2/2020
Intranuclear inclusions þThe cell swells and a large inclusion body forms in the nucleus. 26 10/2/2020
Cytomegalovirus þNuclear & cytoplasmic inclusions 27 10/2/2020
Transmission: CMV þnot highly infectious, virus found in saliva, urine and blood. þinfants and children acquire CMV from other children. þcongenital. In utero, at birth during perinatal period. 28 10/2/2020
Congenital: CMV 29 þthe following possibilities relate to the congenital type. þsevere deformities and death. þsurvive with serious defects - physical and mental. þsurvive with out deformities. þnewborns: - Enlarged liver and spleen, jaundice, capillary bleeding, microcephaly, ocular inflammation. 10/2/2020
Disseminated cytomegalovirus þfever, severe diarrhea, hepatitis, arthritis, pneumonia, high mortality. þactivation of inapparent infection. þalso due to: -immunosuppressive therapy. -cancer. -AIDS. 30 10/2/2020
Virus in blood or organ: þpost transfusion. þpost organ transplant. 31 10/2/2020
Cytomegalovirus mononucleosis: þteenage, young adult similar to other mono. 32 10/2/2020
Transmission: þsaliva, respiratory mucus, milk, urine, semen, cervical secretions, feces and lymphocytes. 33 10/2/2020
Differential Diagnosis: þthe differential diagnosis in neonates must include toxoplasmosis, rubella, herpes simplex, bacterial sepsis. þin adults it must be differentiated from Epstein-Barra and hepatitis A & B. 34 10/2/2020
Laboratory diagnosis: CMV þvirus can be grown from all organs. þmany serological tests. 35 10/2/2020
Treatment: CMV þgancyclovir, foscarnet, hyperimmune CMV immunoglobulin, have some effect. þinterferon does not prevent infection or promote recovery. 36 10/2/2020
Prevention: CMV þno animal can be found that can be infected with CMV. þTwo deterents: þvaccine stimulated antibodies may not be protective. Patients already seropositve can be reinfected. þa vaccine could be oncogenic. 37 10/2/2020
Epidemiology of CMV þ 40 -100% positive for the antibodies. þnewborns 7. 5% positive in the USA & UK. þwoman of child bearing age were 20 -100% positive in many countries that were studied (pregnant virus in the urine). þIV drug users were 100% positive for the antibodies. þhomosexual males were 30% positive for the antibodies - high percentage shed virus. 38 10/2/2020
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