Table of Contents

Component Description

Cytomegalovirus (CMV) antibody testing of stored sera specimens from NHANES 1999-2004 was conducted to estimate the seroprevalence of CMV infection (CMV IgG) in participants aged 6 to 49 years. An optical density measure for IgG is also included in this data release as an estimate of antibody titer.

CMV IgM and IgG avidity among CMV IgG positive samples might not only be helpful in examining the prevalence of IgM and low avidity, but also could provide opportunity of assessing their association with CMV urinary shedding, and the relative attribution to primary or non-primary infection.

Eligible Sample

Participants aged 6 to 49 years from NHANES 2001-2002 with stored sera.

Description of Laboratory Methodology

CMV specific IgG was measured with an ELISA by Quest International, Inc., Miami FL. Sera with values near the ELISA cutoff (approx 5.2% of total) were confirmed with a second ELISA assay by bioMerieux, Inc., Durham, NC. When the results from these 2 tests disagreed (approx. 2.7% of total), an IFA from Bion International, Inc., was used and the result of the IFA was given as the final result.

Optical Density for the IgG test is reported. Optical density was measured with the ELISA assay by Quest International, Inc. and approximately corresponds to antibody titer; a low and positive optical density indicates low antibody titer and a high optical density indicates high antibody titer.

Screening of specimens for CMV IgM was performed using ELISA assay by Diamedix, Miami Lakes, FL and the automated analyzer MAGO. Confirmatory testing for CMV IgM was performed on specimens within a wide range above and below the MAGO test cutoff using the VIDAS ELISA assay by bioMerieux, Inc., Durham, NC.

CMV IgG avidity was measured with an ELISA by bioMerieux, Inc., Durham, NC. (Dollard et al., 2011), 1= low avidity defined as RFV_INDEX < 0.7, 2= High avidity defined as RFV_INDEX ≥ 0.8, and 3= intermediate avidity defined as RFV_INDEX >0.7 and <0.8. IgG avidity is a measure of the overall strength of binding of the IgG antibody to the antigen. As time elapses over 3-4 months following primary infection and synthesis of IgG, the bond between IgG and the antigen becomes stronger. Low IgG avidity indicates a recent primary infection. High IgG avidity suggests that the primary infection occurred in the past.

Data Processing and Editing

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

Data Access: All data are publicly available.

Laboratory Quality Assurance and Monitoring

Commercial reagents were used for all CMV testing. All QC procedures recommended by the manufacturers were followed.

Analytic Notes

There are four variables:

SSCMV: CMV specific IgG results (1=Positive, 2=Negative, 3= Equivocal)

SSCMVOD: CMV IgG Optical Density from the ELISA by Quest International, Inc., Miami FL. Measured in AU/ml which stands for Arbitrary units/ml. Continuous variable - Values range from 0.048 to 3.001. Values reported as “out of range” (i.e. over the detectable range, > 3.00) were assigned values of 3.001.

SSCMIGM: CMV IgM antibody testing results (1=Positive, 2=Negative, 3=Equivocal)

SSCMIGGA: CMV IgG avidity testing results (1=Low, 2=High, 3=Intermediate, 4=Not evaluated)

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 - 49 YEARS

SSCMVOD - CMV optical density from ELISA

Variable Name:
SSCMVOD
SAS Label:
CMV optical density from ELISA
English Text:
CMV optical density from ELISA
Target:
Both males and females 6 YEARS - 49 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.062 to 3.001 Range of Values 5534 5534
. Missing 0 5534

SSCMV - CMV specific IgG results

Variable Name:
SSCMV
SAS Label:
CMV specific IgG results
English Text:
CMV specific IgG results
Target:
Both males and females 6 YEARS - 49 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Positive 3136 3136
2 Negative 2394 5530
3 Equivocal 4 5534
. Missing 0 5534

SSCMIGM - Cytomegalovirus IgM

Variable Name:
SSCMIGM
SAS Label:
Cytomegalovirus IgM
English Text:
Cytomegalovirus IgM
Target:
Both males and females 6 YEARS - 49 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Positive 35 35
2 Negative 2843 2878
3 Equivocal 5 2883
. Missing 2651 5534

SSCMIGGA - Cytomegalovirus IgG Avidity

Variable Name:
SSCMIGGA
SAS Label:
Cytomegalovirus IgG Avidity
English Text:
Cytomegalovirus IgG Avidity
Target:
Both males and females 6 YEARS - 49 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Low 11 11
2 High 163 174
3 Indeterminate 3 177
4 Not evaluated 2706 2883
. Missing 2651 5534