Table of Contents

Component Description

Among children ages 6-19 years who participated in NHANES between 2007 and 2008 and had stored serum samples available, Epstein-Barr virus (EBV) antibody testing was conducted. EBV VCA IgG antibody was measured using a commercial enzyme immunoassay kit.

Eligible Sample

Surplus sera from children aged 6 to 19 years who participated in NHANES years 2007 to 2008.

Description of Laboratory Methodology

25 μL of sample is required for each assay. Specimens, calibrators and controls are pre-diluted 1:21 prior to placing them in the test wells. Cut-off calibrator, controls and subject samples are diluted according to the specific test kit protocol, mixed briefly by vortex to assure good distribution of the sample in the diluent, and then transferred to the appropriately labeled wells and incubated. After washing the wells, conjugate is added with another incubation and wash step following. Substrate is added and allowed to incubate before the addition of stop/color reagent. The plates are read at an absorbance of 450 nm using a reference wavelength of 630 nm. EIA indices are calculated by hand using the formulas in the kit package insert. Data are recorded (1) as Positive (EIA index ≥ 1.10), Negative (EIA index <0.90), or Equivocal (EIA index ≥ 0.90 to 1.09), and (2) as the exact numeric EIA index. The sensitivity of the assay is 96.6% and the specificity is 97.7%.

Data Processing and Editing

Data were submitted after all the antibody testing was complete. The data were not edited.

Laboratory Quality Assurance and Monitoring

Commercial reagents were used for the EBV VCA IgG EIA antibody testing. All QA/QC procedures recommended by the manufacturer were followed.

Analytic Notes

The EIA indices have 4 categorical interpretations.
1. Negative. These samples have an EIA index <0.90.
2. Positive. These samples have an EIA index ≥1.10.
3. Equivocal. These samples have an EIA index ≥ 0.90 to 1.099.*
4. QNS. Quantity insufficient for testing. These samples were assigned an arbitrary index of missing.

*The only way to be certain if subjects with equivocal EIA antibody indices have been infected with EBV is to obtain another specimen from them. Since this is not practical and since this group is only a small fraction of the subjects tested (~0.05%), the cleanest approach to analyzing the data is to exclude them.

Subsample Weights

Sample weights are required to analyze these data properly. Specific sample weights for this subsample are included in this data file and should be used when analyzing these data. When observations were removed from this data file, a new sample weight was created and  added to this data file (WTSSEB2Y). Please refer to the NHANES Analytic Guidelines and the on-line NHANES Tutorial for further details on the use of sample weights and other analytic issues.

References

Codebook and Frequencies

SEQN - Respondent sequence number

Variable Name:
SEQN
SAS Label:
Respondent sequence number
English Text:
Respondent sequence number.
Target:
Both males and females 6 YEARS - 19 YEARS

WTSSE2Y - SSEBV 2 year weights

Variable Name:
WTSSE2Y
SAS Label:
SSEBV 2 year weights
English Text:
Surplus specimen SSEBV 2 year weights
Target:
Both males and females 6 YEARS - 19 YEARS
Code or Value Value Description Count Cumulative Skip to Item
6744.330171 to 131113.34923 Range of Values 1844 1844
0 No lab specimen 0 1844
. Missing 0 1844

SSEBV - Epstein Barr Virus result

Variable Name:
SSEBV
SAS Label:
Epstein Barr Virus result
English Text:
Epstein Barr Virus result
Target:
Both males and females 6 YEARS - 19 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Positive 1371 1371
2 Negative 459 1830
3 Equivocal 13 1843
4 Quantity not sufficient 1 1844
. Missing 0 1844

SSEBVIND - Epstein Barr Virus index

Variable Name:
SSEBVIND
SAS Label:
Epstein Barr Virus index
English Text:
Epstein Barr Virus index
Target:
Both males and females 6 YEARS - 19 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.01 to 7.17 Range of Values 1843 1843
. Missing 1 1844