Which test is used to diagnose acute EBV infection and may be positive early in illness?

• A. Heterophile antibody test (Monospot) or EBV serology
• B. HIV test
• C. TB skin test
• D. ANA

Answer: (A)

Testing for an acute EBV infection relies on antibodies produced in response to the virus. The fast screening test detects heterophile antibodies (the Monospot test), which commonly rise during infectious mononucleosis and can be positive early in the illness. When Monospot is positive, it supports acute EBV infection. If suspicion remains despite a negative Monospot, EBV-specific serology helps, especially VCA IgM, which appears early in the acute phase, with VCA IgG and EBNA appearing later.

The other tests target different diseases—HIV testing for HIV, TB skin testing for tuberculosis, and ANA testing for autoimmune conditions—and do not diagnose EBV infection.