Which test is the specific serologic test for EBV infection?

• A. CBC
• B. EBV-specific IgG antibody testing
• C. Heterophile antibody testing
• D. Throat culture

Answer: (B)

Testing EBV infection relies on antibodies directed against EBV antigens. The heterophile antibody test is a useful screening tool for suspected infectious mononucleosis but isn’t specific to EBV and can be negative early or in young children. A CBC or throat culture won’t directly prove EBV infection either, as they reflect general physiology or bacterial causes rather than the virus itself. The most direct way to confirm EBV involvement is EBV-specific IgG antibody testing, which detects antibodies produced against EBV antigens and provides specific evidence of infection. Patterns of EBV antibodies (like VCA IgM, VCA IgG, and EBNA) further help determine whether the infection is acute or past, but EBV-specific IgG testing is the key for specificity.