The NHANES program suspended field operations in March 2020 due to the coronavirus disease 2019 (COVID-19) pandemic. As a result, data collection for the NHANES 2019-2020 cycle was not completed and the collected data are not nationally representative. Therefore, data collected from 2019 to March 2020 were combined with data from the NHANES 2017-2018 cycle to form a nationally representative sample of NHANES 2017-March 2020 pre-pandemic data. These data are available to the public. Please refer to the Analytic Notes section for more details on the use of the data.
Epstein-Barr virus (EBV) is one of the most common human viruses. Most people get infected with EBV at some point in their lives, with an estimated seroprevalence of 90–95%. EBV spreads most commonly through bodily fluids, primarily saliva. EBV is the most common cause of infectious mononucleosis and has been associated with other conditions, including multiple sclerosis and cancers. People with weakened immune systems may develop more severe symptoms and complications from EBV infection. They may also have more severe illnesses caused by EBV infection.
Examined participants aged 6-59 years were eligible.
Stored serum specimens were processed, stored, and shipped to the National Center for Immunization and Respiratory Diseases Laboratories, Centers for Disease Control and Prevention, Atlanta, GA for analysis.
The lab method for this component in the NHANES 2017–March 2020 cycle was different from the previous EBV serology files (e.g. SSEBV_F).
Epstein-Barr Virus (EBV) ELISA
The EBV ELISA test system used was an FDA-approved test for the qualitative detection of IgG class antibodies to Epstein-Barr virus in human serum utilizing the viral capsid antigen (VCA). This test is used to evaluate serological evidence of previous infection with EBV and alone cannot distinguish primary infection from reactivation or latency. IgG antibody titers to VCA peak 30 days after infection, decline slowly over time but last indefinitely. EBV ELISA is very specific, sensitive, and easy to use with an assay time of approximately 1.5 hours. This is in comparison to other assays for the detection of EBV antibodies, such as indirect immunofluorescence.
| Sensitivity | Specificity | Concordance | |
|---|---|---|---|
| Epstein-Barr Virus | 95.3% (90.9-99.6) | 94.1% (88.3-99.8) | 95.2% (90.8-99.5) |
Data shown refers to performance characteristics generated during FDA submission.
A working dilution of the serum specimens, positive control, negative control, and calibrators in diluent buffer was prepared and 100 µL of diluted specimens, controls, and calibrators was added to each well. The plate was incubated for 30 minutes at room temperature (15-25oC), then washed 5 times with wash buffer. After washing, 100 µL of conjugated antibody was added to each well and the plate was incubated at room temperature (15-25oC). After 30 minutes the plate was washed again 5 times with wash buffer and 100 µL of TMB solution was added to each well. After a 15 minutes incubation at room temperature (15-25oC), 50 µL of Stop Solution was added and the plate was read using a Tecan plate reader with absorbance of each well at 450 nm using a reference wavelength of 620-650nm. Plates were confirmed to pass quality controls and specimen results were determined based off established optical density (OD) value cutoffs.
Quality control was performed for each plate using a reagent blank well, a negative control well, a positive control well, and a calibrator run in triplicate. For a plate to pass quality control checks, all controls must be within kit established parameters. The mean of the three calibrator wells is determined, and all three calibrators must not differ by more than 15% of the mean. The raw OD value of the negative control must be ≤0.250, the calibrator ≥0.300, and the positive control ≥0.500. The calculated interpretation of the negative control must be ≤0.9 and the calculated interpretation of the positive control must be ≥1.25. If any of the above conditions were not met, the run was considered invalid. All specimens that resulted in an initial equivocal result were run again in duplicate and the final result was based on the majority result of the three results. An additional 10% of randomly selected samples representing each plate run were selected to be repeated for testing to ensure quality between runs and plates.
Data were received after all analyses were complete. The data were reviewed. Incomplete data or improbable values were sent to the performing laboratory for confirmation.
Derived variables were created in this data file:
SSEBVI
EBV Viral Capsid Antigen IgG Antibody Interpretation (SSEBVI) was coded as 1 (positive) when EBV Viral Capsid Antigen IgG Antibody ISR Value (SSEBVQ) was greater than or equal to 1.10, coded as 2 (negative) when SSEBVQ was less than or equal to 0.90, and coded as 3 (equivocal) when SSEBVQ was greater than 0.90 and less than 1.10.
The COVID-19 pandemic required suspension of NHANES 2019-2020 field operations in March 2020 after data were collected in 18 of the 30 survey locations in the 2019-2020 sample. Data collection was cancelled for the remaining 12 locations. Because the collected data from 18 locations were not nationally representative, these data were combined with the previous cycle (2017-2018) to create a 2017-March 2020 pre-pandemic data file. A special weighting process was applied to the 2017-March 2020 pre-pandemic data file. The resulting sample weights in the present file should be used to calculate estimates from the combined cycles. These sample weights are not appropriate for independent analyses of the 2019-2020 data and will not yield nationally representative results for either the 2017-2018 data alone or the 2019-March 2020 data alone. Please refer to the NHANES website for additional information for the NHANES 2017-March 2020 pre-pandemic data.
Refer to the 2017-2018 and 2019-2020 Laboratory Data Overviews for general information on NHANES laboratory data.
There are over 800 laboratory tests performed on NHANES participants. However, not all participants provided biospecimens or enough volume for all the tests to be performed. Additionally, availability of specimens for surplus projects is lower than for other laboratory tests performed on NHANES participants. The specimen availability can also vary by age or other population characteristics. Analysts should evaluate the extent of missing data in the dataset related to the outcome of interest as well as any predictor variables used in the analyses to determine whether additional re-weighting for item non-response is necessary.
Please refer to the NHANES Analytic Guidelines and the on-line NHANES Tutorial for details on the use of sample weights and analytic issues.
Subsample Weights
The analytes included in this dataset were measured in examined participants aged 6-59 years. Special sample weights are required to analyze these data properly. Specific sample weights for this subsample, WTSSMMPP, are included in this data file and should be used when analyzing these data. The sample weights created for this file used the examination sample weight, i.e., WTMECPRP, as the base weight. The base weight was adjusted for additional nonresponse to these lab tests and re-poststratified to the population total using sex, age, and race/Hispanic origin. Participants who were part of the eligible population, but who did not provide a serum specimen, or did not have sufficient volume of biospecimens, or who did not give consent for their specimens to be used for future research are included in the file, but they have a sample weight assigned “0” in their records.
Demographic and Other Related Variables
The analysis of NHANES laboratory data must be conducted using the appropriate survey design and demographic variables. The NHANES 2017-March 2020 Pre-Pandemic Demographics File contains demographic data, health indicators, and other related information collected during household interviews as well as the sample design variables. The recommended procedure for variance estimation requires use of stratum and PSU variables (SDMVSTRA and SDMVPSU, respectively) in the demographic data file.
This laboratory data file can be linked to the other NHANES data files using the unique survey participant identifier (i.e., SEQN).
Detection Limits
There are no upper or lower limits of detection for this assay, and all results are reported as is.
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 to 425710.13599 | Range of Values | 9057 | 9057 | |
| . | Missing | 0 | 9057 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| -0.06 to 6.03 | Range of Values | 6738 | 6738 | |
| . | Missing | 2319 | 9057 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 1 | Positive | 5648 | 5648 | |
| 2 | Negative | 1060 | 6708 | |
| 3 | Equivocal | 30 | 6738 | |
| . | Missing | 2319 | 9057 |