Epstein-barr Virus Flashcards
1
Q
Classification:
A
Family: Herpesviridae
Genus: Lymphocryptovirus
Species:
Common name: Epstein-Barr virus
Official name: HHV-4r
2
Q
Characteristics
A
Enveloped virus Icosahedral nucleocapsid Linear dsDNA No virion polymerase One serotype
3
Q
Transmission
A
Virus found in human oropharynx and B lymphocytes
> > > It is transmitted primarily by saliva
4
Q
Pathogenesis
A
- infection begins In the mucosa of the oropharynx
- spreads to the cervical lymph nodes, then travels via the blood to the liver and spleen —> splenomegaly due to T-cell proliferation
- EBV establishes latency in B lymphocytes
EBV envelope glycoproteins binds CD21 to infect B cells
5
Q
Disease
A
- Infectious mononucleosis
- risk factor for developing cancer
It is associated with:
- B-cell lymphoma:
»> Hodgkin’s lymphoma = Reed-Sternberg cells that look like “owl’s eyes”
»> non-Hodgkin’s lymphoma: Endemic or African Burkett lymphoma- large jaw lesion and swelling ~ develop in ileocaecum and peritoneum - Nasopharyngeal carcinoma (Asian patients)
- Oral hairy leukoplakia (non cancerous lesions (does not develop into squamous cell carcinoma), occurs at lateral part of tongue, similar to Candida, but unlike Candida, it can’t be scraped out of the tongue —> occurs particularly in HIV patients)
6
Q
Microbiological diagnosis
A
- The virus is rarely isolated
- Lymphocytosis, including atypical lymphocytes (Downey cells)
»> reactive cytotoxic CD8+ T cells and NK cells are seen in blood smears. - Rapid diagnosis: Monospot test - positive
> > > heterophil antibody agglutinate sheep or horse RBCs
7
Q
Treatment and prevention
A
Treatment:
- no antiviral therapy
- supportive therapy is available
- avoid contact sports to avoid splenomegaly (due to splenic rupture)
!! If mistakenly given ampicillin or amoxicillin (presupposing steptococcal pharyngitis) —> maculopapular rash develops
Prevention:
No vaccine or drug
