Which laboratory test may be necessary for a definitive diagnosis of EBV infection in the early stages?

In the early stages of an Epstein-Barr virus (EBV) infection, the presence of EBV-specific antibodies is crucial for making a definitive diagnosis. The EBV-specific antibody test includes the detection of heterophile antibodies which are typically associated with infectious mononucleosis, a common manifestation of EBV infection.

During the initial stages of the infection, classic symptoms may be present such as fever, sore throat, and lymphadenopathy, but routine laboratory tests, such as a complete blood count or liver function tests, may not provide enough specificity to confirm the diagnosis. A complete blood count might show atypical lymphocytes, but it lacks the specificity needed for EBV. Liver function tests may indicate hepatocellular injury, commonly present in cases of infectious mononucleosis, but they are not definitive for EBV itself. Serum creatinine is unrelated to the diagnosis of EBV infection.

Therefore, identifying the presence of EBV-specific antibodies can help confirm the diagnosis early during the infection, making this test essential for achieving a definitive diagnosis of EBV infection in the early stages.