Pathology Associates Of Lexington, P.A.
Pathology Associates Of Lexington, P.A.
Pathology Associates Of Lexington, P.A.
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         Infectious Mono Test, blood

"Monospot" test, blood

We used the Organon Monosticon kit until 5/2004 (switched to Seradyn Color Slide II), and this is a screening test for EBV-type (Epstein-Barr virus...HHV-4) acute infection. IFA serology is helpful to diagnose those monospot-negative cases actually due to EBV. Heterophile antibodies can exist in a patient, very infrequently (2-3% of positive cases), from some other cause than EBV.

Situations with negative test:

  • patient has EBV "mono" but too early for positive test

  • real "false negative" rate of about 5-7%

  • follow-up EBV test method may have only 78% or less sensitivity (high false negative rate); if CBC smear is negative for atypical lymphocytes AND the total, absolute lymphocyte count is <4000, then it is highly likely the this is a true negative Monospot and EBV test1

  • patient actually has a sore throat, and lymph nodes, and atypical lymphocytes on a CBC report, and tired due to another (such as CMV) virus

  • patient actually has a sore throat and, lymph nodes,  and tired due to "strep throat" which has been already partially treated with antibiotics so that "strep throat" rapid test AND culture are both negative

  1. leukemia or lymphoma2
  2. malaria2
  3. rubella2
  4. hepatitis, viral2
  5. pancreatic ca.2
  6. present for years in some persons for no known reason2

Situations with positive test:

active EBV "mono" infection
2-3% of positives (false positives) are due to something else1


  1. Tetrault vs. Doyle, letters exchange, Arch. Path. & Lab. Med., 125(7):858-859, 7/2001.
  2. Interpretation of Diagnostic Tests, Wallach, 2000, 7th Ed., pages 844-845.

Synonyms: infectious mono test; mononucleosis test

(posted 2002; latest update 13 May 2004)

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