EBV Flashcards
What is the most common cause of infectious mononucleosis?
Epstein-Barr virus (EBV).
Infectious mononucleosis (IM) is a viral syndrome most commonly due to Epstein-Barr virus, with manifestations that commonly include fever, fatigue, exudative pharyngitis, lymphadenopathy, and hepatosplenomegaly. Liver function test results may be mildly elevated. Patients with IM may develop an erythematous exanthematous rash, which is usually maculopapular, urticarial, or morbilliform and most often erupts after inappropriate administration of amoxicillin or ampicillin. The etiology of this well-known phenomenon is unclear, although it may be an immune-mediated response to circulating antibodies against penicillin derivatives. The rash is not considered a true antibiotic allergy and will resolve spontaneously over time with observation and supportive care.
To which virus family does Epstein-Barr virus belong?
Herpesvirus family (Herpesviridae)
What type of genetic material does EBV have?
Double-stranded DNA (dsDNA)
Is Epstein-Barr virus enveloped or non-enveloped?
Enveloped
How is Epstein-Barr virus primarily transmitted?
Through saliva (‘kissing disease’)
Which cell surface receptor does EBV bind to?
CD21 on B cells
What glycoprotein of EBV binds to CD21?
GP350
What are the classic symptoms of infectious mononucleosis?
- Severe fatigue
- Fever
- Pharyngitis
- Tonsillar exudates
- Tender posterior cervical lymphadenopathy
What type of immune response is seen in EBV infection?
Peripheral lymphocytosis with reactive lymphocytes (Downy cells).
What are Downy cells?
Atypical lymphocytes with abundant basophilic cytoplasm seen in EBV infection.
What complications arise from lymphoid proliferation in EBV infection?
Splenomegaly and enlarged lymph nodes.
Why would LFTs be checked when a patient has mononucleosis?
Transient hepatitis.
Where does Epstein-Barr virus remain latent?
In B cells.
Which malignancies are associated with Epstein-Barr virus?
- Hodgkin lymphoma
- Burkitt lymphoma
- non-Hodgkin lymphoma
- nasopharyngeal carcinoma
- oral hairy leukoplakia
What are the histological features of Hodgkin lymphoma?
Reed-Sternberg cells (large abnormal B cells with owl-eye nuclei).
What is endemic Burkitt lymphoma?
A subtype of Burkitt lymphoma in children from equatorial Africa, often presenting with jaw swelling.
Which malignancy is particularly common in Southeast Asia and strongly associated with EBV?
Nasopharyngeal carcinoma.
What condition is associated with EBV infection in HIV patients?
Oral hairy leukoplakia.
What test is commonly used for rapid diagnosis of infectious mononucleosis?
Monospot test (detects heterophile IgM antibodies).
Why is the Monospot test no longer recommended by the CDC?
Due to low sensitivity and specificity.
What is the gold standard test for diagnosing EBV infection?
Serum testing for Epstein-Barr virus-specific antibodies.
What is the clinical course for mononucleosis and how does this evolve overtime?
Most patients with IM will have an uncomplicated course and symptoms will resolve spontaneously within weeks of onset. However, persistent fatigue is common and may exist for months (with some patients experiencing chronic fatigue for >6 months). Women and individuals with preexisting mood disorders may be at increased risk for prolonged fatigue.
Is mononucleosis considered to be an STI?
No. Although Epstein-Barr virus can be isolated in cervical discharge and semen, there is no evidence that these fluids are more contagious than saliva, and close sexual contacts are not considered to be at higher risk of infection than other contacts. Testing is not indicated for any contact who is asymptomatic.
Why should patients with infectious mononucleosis avoid contact sports?
Risk of splenic rupture due to splenomegaly.
How long should patients avoid contact sports after EBV infection?
At least 4 weeks (3 weeks for regular sports)
What happens if a patient with EBV is mistakenly treated with amoxicillin or penicillin?
They develop a maculopapular rash. This rash rash is commonly described as a diffuse, erythematous, blanching, maculopapular rash is seen on the chest, abdomen, and extremities. The rash is not considered a true antibiotic allergy and will resolve spontaneously over time with observation and supportive care.
Why do patients with EBV develop a rash after receiving amoxicillin?
Immune-mediated reaction due to abnormal immune response to antibiotics. This rash rash is commonly described as a diffuse, erythematous, blanching, maculopapular rash is seen on the chest, abdomen, and extremities. The rash is not considered a true antibiotic allergy and will resolve spontaneously over time with observation and supportive care. The rash does not correlate with increase risk of spreading this infection.
Are corticosteroids or antihistamines used to treat the rash that develops after administering penicillin in an EBV infection, when would these be indicated?
The rash will not improve if treated with medications used to combat allergic reactions (eg, corticosteroids, antihistamines). The rare occasions in which corticosteroids are indicated in the management of IM include severe sequelae such as hemolytic anemia or airway obstruction.
