From the Guidelines
The most effective way to test for Epstein-Barr virus (EBV) is through a combination of the monospot test and EBV-specific serologic testing, including tests for viral capsid antigen (VCA) IgM and IgG, early antigen (EA), and Epstein-Barr nuclear antigen (EBNA) 1, 2. To diagnose EBV infection, the following steps can be taken:
- The monospot test, also known as the heterophile antibody test, can quickly identify infectious mononucleosis caused by EBV, but it may be falsely negative in up to 10% of cases, especially in younger children 1, 2.
- If the monospot test is negative but there is a strong clinical suspicion for EBV infection, EBV-specific serologic testing can be performed to confirm the diagnosis 2.
- The presence of VCA IgM indicates a current or recent infection, while VCA IgG shows past exposure, and EBNA antibodies typically appear 2-4 months after infection and remain detectable for life 2.
- For more sensitive detection, especially in immunocompromised patients, PCR tests can directly measure EBV DNA in blood, but this should be used in conjunction with serologic testing to confirm the diagnosis 3, 2. Some key points to consider when testing for EBV include:
- The monospot test can be used as an initial screening test, but it should be followed up with more specific testing if the results are negative or if there is a strong clinical suspicion for EBV infection 1, 2.
- EBV-specific serologic testing can help differentiate between current and past infections, and can also help identify patients who are at risk for complications such as lymphoproliferative disease 2.
- PCR tests can be used to detect EBV DNA in blood, but this should be used in conjunction with serologic testing to confirm the diagnosis, especially in immunocompromised patients 3, 2.
From the Research
Testing for EBV
To test for Epstein-Barr virus (EBV) infection, several serological tests can be used, including:
- Viral capsid antigen (VCA) IgG and IgM antibodies
- EBV nuclear antigen (EBNA)-1 IgG antibodies
- Heterophile antibodies
- Anti-EBV IgG and IgM antibodies by immunoblotting
- Viral genome using molecular biology methods 4, 5, 6
Interpretation of Serological Patterns
The interpretation of EBV serological patterns can be challenging due to the presence of multiple antibodies. However, the use of certain markers, such as VCA IgG, VCA IgM, and EBNA-1 IgG, can help distinguish between acute and past infection 4. Additionally, the use of IgG avidity testing and immunoblotting can aid in the interpretation of serological patterns 7.
Methods for Serological Diagnosis
Several methods are available for the serological diagnosis of EBV infection, including:
- Immunofluorescence assay (IFA)
- Enzyme-linked fluorescent assay (ELFA)
- Enzyme immunoassay (EIA)
- Immunochromatographic assay (ICA)
- Immunoblot assay These methods vary in their performance and agreement with IFA, which is considered the "gold standard" test 8.
Diagnostic Approach
A diagnostic approach to EBV infection may involve the use of multiple tests and markers to determine the status of the infection. This may include: