Epstein-Barr Virus Infections: 5 Things Primary Care Physicians Need to Know Now

January 28, 2012

No typical clinical signature; variable serology; 10% atypical lymphocytes. Here, read more about the essentials in detection and treatment of EBV infection.

1. There is no typical clinical signature.
Most primary infections with Epstein-Barr virus (EBV) are either nonspecific or asymptomatic. Classical infectious mononucleosis is seen primarily during adolescence or young adulthood. Reactivations are common, and are essentially always related to asymptomatic excretion of the virus in saliva.

2. Serology can be variable.
The monospot (heterophile) test for mononucleosis detects an antibody to a non-viral coded antigen. It is often negative during the first week of illness and then present for a variable amount of time. Non-EBV causes of mononucleosis (such as cytomegalovirus [CMV], Toxoplasma gondii, and primary HIV) do not cause a positive heterophile antibody.

3. Serodiagnosis requires certain specific criteria.
Specific primary EBV serodiagnosis requires positive anti-early antigen (EA) and IgM anti–viral capsid antigen (VCA), with a negative anti-EB nuclear antigen (EBNA). In convalescence, IgG anti-VCA, and anti-EBNA are present. Sometimes, patients have anti-EA as well.

4. Check for atypical lymphocytes.
Finding more than 10% atypical lymphocytes (Downey cells) in the peripheral blood is highly suggestive of EBV rather than other infectious causes of mononucleosis. However, keep in mind that reactions to certain drugs, such as phenytoin and para-aminosalicylate sodium, can also cause this.

5. Protect the spleen.
It is reasonable to restrict patients with mononucleosis from contact sports and weight lifting for perhaps 3 to 4 weeks after onset of illness because of a risk of splenic rupture.

Bonus Point
The atypical lymphocyte, which develops as part of the immune response to EBV infection, is a T lymphocyte. It is not the B lymphocyte, in which the EBV replicates.

References:

Resources
•Luzuriaga K, Sullivan JL. Infectious mononucleosis. N Engl J Med. 2010;362:1993-2000.
•Odumade OA, Hogquist KA, Balfour HH. Progress and problems in understanding and managing Epstein-Barr virus infections. Clin Microbiol Rev. 2011;24:193-209.