Which EBV marker is most commonly used to indicate an acute EBV infection?

Which EBV marker is most commonly used to indicate an acute EBV infection?

• A. anti-VCA IgG
• B. anti-VCA IgM
• C. anti-EBNA
• D. anti-EA

Answer: (B)

The test is about recognizing which EBV antibody signal best marks a new, active infection. When the body first encounters EBV, it rapidly makes IgM antibodies to the viral capsid antigen (VCA). Anti-VCA IgM rises early during acute illness and then declines over weeks to months, making it a clear indicator of a current infection. In contrast, anti-VCA IgG also appears early but remains for life, so its presence alone doesn’t prove the infection is new. Antibodies to EBNA appear later, indicating past infection or latency rather than acute disease. Early antigen (EA) antibodies can be present during active replication but are less consistently present and less specific for acute infection. So, anti-VCA IgM is the best marker for indicating an acute EBV infection because it appears promptly during the active phase and is more specific to recent infection than the other markers.

The test is about recognizing which EBV antibody signal best marks a new, active infection. When the body first encounters EBV, it rapidly makes IgM antibodies to the viral capsid antigen (VCA). Anti-VCA IgM rises early during acute illness and then declines over weeks to months, making it a clear indicator of a current infection. In contrast, anti-VCA IgG also appears early but remains for life, so its presence alone doesn’t prove the infection is new. Antibodies to EBNA appear later, indicating past infection or latency rather than acute disease. Early antigen (EA) antibodies can be present during active replication but are less consistently present and less specific for acute infection.

So, anti-VCA IgM is the best marker for indicating an acute EBV infection because it appears promptly during the active phase and is more specific to recent infection than the other markers.