1. Epstein-Barr virus Cytomegalovirus
Herpes Viruses
Epstein-Barr virus
Cytomegalovirus

2. CMV & EBV Outline Structure Classification Multiplication
Clinical manifestations
Epidemiology
Diagnosis
Control
Baron’s Web Site

3. Latent Infections
ALL herpes viruses can establish latent infections. The viral genome may become incorporated into the host DNA or remain extrachromosomal
Latent viruses can be reactivated by stress, menstruation or uv light
Reactivation may be asymptomatic or lead to mild or severe disease.

4. Herpes Diagnosis Isolation of virus by tissue culture
herpevirinae cause cytopathic effects
intranuclear fluorescence of scrapings using fluorescent antibodies
PCR being developed
CMV retiniitis is diagnosed clinically

5. Epstein Barr Virus

6. Epstein-Barr virus
virus established in lymphoid tissue and salivary glands - is excreted from salivary glands.
Epstein-Barr virus is a transforming DNA virus.

7. EBV History
infectious 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 recipients
Burkitt’s lymphoma (B cell carcinoma) in E. africans
nasopharyngeal carcinoma in Chinese

10. Classic Mononucleosis
infectious mononucleosis has an incubation period of 30 to 50 days.
high fever, malaise, myalgia, cervical lymphadenopathy, splenomegaly, hepatomegaly
high fever, pharyngitis, grey-white pharyngeal exudate, skin rash
atypical 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 symptoms
differential blood count - lymphocytosis, neutropenia, large atypical cells.
heterophile antibodies
antibodies to EBV nuclear antigen
antibodies to EBV capsid antigen

13. Infectious Mononucleosis Transmission
direct oral contact
exposure to saliva
fomites
arthropod 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 gland
viremia
latent in throat and blood
subclinical 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 defective
Co-carcinogen, chemical, cigarette smoke

18. Transformed cells: Not warts: Papovavirus lose contact inhibition
continue to divide
form random aggregations
can become invasive
Not warts: Papovavirus

19. Primary Hepatocellular Carcinoma
Icteric symptoms:
jaundice, dark urine, pale stools
Highest incidence:
Central Africa
Southeast China
Pacific Islands, Borneo, Sarawak, Taiwan
250,000 to1,000,000 deaths worldwide per year
U.S.A deaths / year

20. Human T-cell Leukemia Virus
HTLV1 & HTLV2
retroviruses with no oncogenes
Adult T-cell leukemia and lymphoma - Southern Japan, Carribean Islands, West Africa

21. Epstein Barr Southern China, Asia
suspect co-carcinogen: - nitrosamines in salted fish
oncogenes not reported.

22. Burkitts Lymphoma East Africa, Papua New Guinea
at risk: year old males
tumor of immature B-cells

23. Human Papillomavirus cervical, penile, vulval, and rectal cancer
viral genome integrated into host genome
Co-carcinogens - cigarette smoke - HSV herpes

24. Cytomegalovirus

25. Cytomegalovirus
Urine isolate

26. Intranuclear inclusions
The cell swells and a large inclusion body forms in the nucleus.

27. Cytomegalovirus
Nuclear & cytoplasmic inclusions

28. Transmission: CMV
not 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: CMV
the 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.

33. Transmission:
saliva, respiratory mucus, milk, urine, semen, cervical secretions, feces and lymphocytes.

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: CMV
gancyclovir, 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.