Table of Contents

Component Description

Susceptibility to measles, mumps, rubella, and varicella (MMRV) for the purpose of monitoring the susceptibility of the U.S. population to each of these highly contagious, infectious diseases. Serological testing for antibodies for MMRV among NHANES participants has been a primary means for determining the impact of the vaccination program in the U.S. and would serve to document progress toward achieving the Healthy People 2010 goals related to all four of these diseases. In addition, documenting trends in immunity is necessary to estimate duration of protection in the US population. Documentation of waning immunity in a population with high vaccination coverage and low probability of boosting due to exposure to wild virus will have implications on future vaccination policy in the US.

Eligible Sample

All participants aged 6 to 49 years are eligible to be tested.

Description of Laboratory Methodology

Serum specimens are processed, stored, and shipped to the National Center for Immunization and Respiratory Disease Laboratories. Detailed specimen collection and processing instructions are discussed in the NHANES Laboratory/Medical Technologists Procedures Manual (LPM.)\

Measles antibody

The Wampole Measles IgG ELISA test system is designed to detect IgG class antibodies to Measles virus in human sera. Wells of plastic microwell strips are sensitized by passive absorption with antigen. The test procedure involves three incubation steps: 1) test sera (properly diluted) are incubated in antigen coated microwells. Any antigen specific antibody in the sample will bind to the immobilized antigen. The plate is washed to remove unbound antibody and other serum components, 2) peroxidase conjugated goat anti-human IgG (y chain specific) is added to the wells and the plate is incubated. The conjugate will react with Measles antibody immobilized on the solid phase in step 1. The wells are washed to remove unreacted conjugate, 3) the microwells containing immobilized peroxidase conjugate are incubated with peroxidase substrate solution. Hydrolysis of the substrate by peroxidase produces a color change. After a period of time the reaction is stopped and the color intensity of the solution is measured photometrically. The color intensity of the solution depends upon the antibody concentration in the original test sample.

Mumps antibody

The Wampole Mumps IgG ELISA test system is designed to detect IgG class antibodies to Mumps virus in human sera. Wells of plastic microwell strips are sensitized by passive absorption with antigen. The test procedure involves three incubation steps: 1) test sera (properly diluted) are incubated in antigen coated microwells. Any antigen specific antibody in the sample will bind to the immobilized antigen. The plate is washed to remove unbound antibody and other serum components, 2) peroxidase conjugated goat anti-human IgG (y chain specific) is added to the wells and the plate is incubated. The conjugate will react with Mumps antibody immobilized on the solid phase in step 1. The wells are washed to remove unreacted conjugate, 3) the microwells containing immobilized peroxidase conjugate are incubated with peroxidase substrate solution. Hydrolysis of the substrate by peroxidase produces a color change. After a period of time the reaction is stopped and the color intensity of the solution is measured photometrically. The color intensity of the solution depends upon the antibody concentration in the original test sample.

Rubella antibody

The Wampole Rubella IgG ELISA test system is designed to detect IgG class antibodies to Rubella virus in human sera. Wells of plastic microwell strips are sensitized by passive absorption with antigen. The test procedure involves three incubation steps: 1) test sera (properly diluted) are incubated in antigen coated microwells. Any antigen specific antibody in the sample will bind to the immobilized antigen. The plate is washed to remove unbound antibody and other serum components, 2) peroxidase conjugated goat anti-human IgG (y chain specific) is added to the wells and the plate is incubated. The conjugate will react with Rubella antibody immobilized on the solid phase in step 1. The wells are washed to remove unreacted conjugate, 3) the microwells containing immobilized peroxidase conjugate are incubated with peroxidase substrate solution. Hydrolysis of the substrate by peroxidase produces a color change. After a period of time the reaction is stopped and the color intensity of the solution is measured photometrically. The color intensity of the solution depends upon the antibody concentration in the original test sample.

Varicella antibody

Varicella-zoster virus IgG antibody in serum -- gpELISA
The presence of IgG antibody to varicella-zoster virus (VZV) is measured using an enzyme immunoassay (EIA) developed by the staff of the National VZV Laboratory (NCID/DVRD/VEHB). This method has been validated against a number of other laboratory-based VZV serologic methods and performs comparably to all of them (manuscript in preparation). Lentil-lectin-purified glycoprotein antigens derived from VZV-infected human fibroblast cells (obtained through CRADA with Merck & Co.) is coated on the wells of a 96-well microtiter plate, which is subsequently incubated with a diluted test specimen. Control (normal tissue) antigen (also obtained from Merck & Co.) is also prepared from uninfected fibroblasts and is plated separately into different wells and incubated with test serum to account for any nonspecific antibody reactivity. After unbound serum components are removed by washing, an antibody-enzyme conjugate, consisting of anti-human IgG antibody coupled to alkaline phosphatase, is added to wells and incubated. The conjugate binds only to human IgG antibodies that are in turn bound to the antigen coated on the plates. A colorimetric substrate for the enzyme is added to the wells and incubated for a sufficient time to permit color development, at which point the reaction is stopped chemically. The enzyme-substrate reaction results in a yellow-colored product that can be measured using a spectrophotometer set to a wavelength of 405 nm. gpELISA has been demonstrated to have both higher sensitivity and specificity than whole cell ELISA; since the antigens are available in limited supply, however, it is used to test all specimens that test in the negative or equivocal range by whole cell ELISA and to detect seroconversion to vaccine (which requires the higher sensitivity).

Varicella-zoster virus IgG antibody in serum – Whole Cell ELISA
The presence of IgG antibody to varicella-zoster virus (VZV) is measured using an enzyme immunoassay (EIA) developed by the staff of the National VZV Laboratory (NCID/DVRD/VEHB). This method has been validated against a number of other laboratory-based VZV serologic methods and performs comparably to all of them (manuscript in preparation). Detergent-extracted antigen derived from VZV-infected human fibroblast cells is coated on the wells of a 96-well microtiter plate, which is subsequently incubated with a diluted test specimen. Control (normal tissue) antigen is also prepared from uninfected fibroblasts and is plated separately into different wells and incubated with test serum to account for any nonspecific antibody reactivity. After unbound serum components are removed by washing, an antibody-enzyme conjugate, consisting of anti-human IgG antibody coupled to alkaline phosphatase, is added to wells and incubated. The conjugate binds only to human IgG antibodies that are in turn bound to the antigen coated on the plates. A colorimetric substrate for the enzyme is added to the wells and incubated for a sufficient time to permit color development, at which point the reaction is stopped chemically. The enzyme-substrate reaction results in a yellow-colored product that can be measured using a spectrophotometer set to a wavelength of 405 nm.

Data Processing and Editing

Read the General Documentation on Laboratory Data file for detailed data processing and editing protocols. The analytical methods are described in the Analytic Notes section below.

Analytic Notes

The analysis of NHANES laboratory data must be conducted with the key survey design and basic demographic variables. The NHANES Household Questionnaire Data Files contain demographic data, health indicators, and other related information collected during household interviews. They also contain all survey design variables and sample weights for these age groups. The phlebotomy file includes auxiliary information such as the conditions precluding venipuncture. The household questionnaire and phlebotomy files may be linked to the laboratory data file using the unique survey participant identifier SEQN.

If varicella-zoster virus IgG (whole cell) test is positive or if varicella-zoster virus IgG (gp) test is positive then the confirmed varicella zoster result is positive. if varicella-zoster virus IgG (gp) test is negative or equivocal then the confirmed varicella zoster result is negative.

Exam sample weights should be used for analyses. 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.

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

LBXMEA - Measles antibody (IgG)

Variable Name:
LBXMEA
SAS Label:
Measles antibody (IgG)
English Text:
Measles antibody (IgG)
Target:
Both males and females 6 YEARS - 49 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.028 to 9.71 Range of Values 5054 5054
. Missing 598 5652

LBXMUM - Mumps antibody (IgG)

Variable Name:
LBXMUM
SAS Label:
Mumps antibody (IgG)
English Text:
Mumps antibody (IgG)
Target:
Both males and females 6 YEARS - 49 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.09 to 8.091 Range of Values 5054 5054
. Missing 598 5652

LBXRUB - Rubella antibody (IgG)

Variable Name:
LBXRUB
SAS Label:
Rubella antibody (IgG)
English Text:
Rubella antibody (IgG)
Target:
Both males and females 6 YEARS - 49 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.007 to 6.82 Range of Values 5054 5054
. Missing 598 5652

LBDVWCGP - Varicella antibody, confirmed

Variable Name:
LBDVWCGP
SAS Label:
Varicella antibody, confirmed
English Text:
Varicella antibody, confirmed
Target:
Both males and females 6 YEARS - 49 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Positive 4940 4940
2 Negative 114 5054
. Missing 598 5652