A 20-year-old college student has fever, pharyngitis, cervical lymphadenopathy, and splenomegaly. Serology shows: VCA IgM positive, VCA IgG positive, EBNA-1 IgG negative, heterophile antibody negative. The most likely explanation is:
- A Acute Epstein-Barr virus infectious mononucleosis, heterophile test falsely negative ✓
- B Past EBV infection with reactivation
- C Chronic active EBV disease
- D CMV mononucleosis mimicking EBV
Correct answer: A. Acute Epstein-Barr virus infectious mononucleosis, heterophile test falsely negative
Explanation
In acute primary EBV infection, VCA IgM appears first and EBNA develops only 2 to 4 months after onset, so the pattern VCA IgM positive with EBNA negative is diagnostic of acute infection. The heterophile (Paul Bunnell) test can be negative in up to 25 percent of cases in the first week and in young children, so a negative heterophile result does not exclude mononucleosis. Past infection would show EBNA positivity with absent VCA IgM.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.