Human papillomavirus (HPV) infection is the most common sexually transmitted infection in the United States, and persistent infection with certain types of HPV can progress to cancer. HPV-attributable cancers include cervical, vaginal, vulvar, anal, penile, and oropharyngeal cancers. NHANES offers a unique opportunity to assess the prevalence of HPV infection in the general population and the impact of HPV vaccination.
HPV vaccination was introduced in the national immunization program for females in 2006 and for males in 2011. Reducing infections of HPV types prevented by the vaccine in young adults and increasing the proportion of adolescents vaccinated for HPV are both Healthy People 2030 objectives. Knowledge of the national prevalence of HPV infection is critical for planning vaccination strategies and monitoring the impact of vaccination in the United States. Seroprevalence reflects current and past exposure to HPV as well as presence of vaccine-induced antibody and can provide important information about HPV epidemiology and vaccination.
Examined participants aged 14 to 59 years were eligible.
M9ELISA is an assay developed for the detection of 9 HPV types, which includes both qualitative and quantitative results.
M9ELISA allows for simultaneous detection of antibodies to HPV 6, 11, 16, 18, 31, 33, 45, 52, and 58 in one microwell (Panicker et. al., 2021). Virus-like particles (VLP), self-assembled HPV L1+L2 protein capsids that resemble intact virions, are used as antigen in the assay. HPV-type specific antibodies present in test samples will bind to type-specific conformational epitopes on the VLPs adsorbed onto the surface of the microwell. Bound human IgG is detected with a SulfoTAGTM Anti-Human IgG using electrochemiluminescent detection on the Meso Scale Discovery (MSD) plate reader that generates relative light units (RLU). The amount of antibodies in the sample is estimated relative to a reference sample using the parallel line method and reported in International Units/milliliter (IU/mL). Samples are scored as positive or negative using a pre-determined “cut-off” level. The assay is used for research purposes and does not have clinical relevance.
Refer to the Laboratory Method Files section for a detailed description of the laboratory methods used.
M9ELISA – Multiplexed VLP-based IgG ELISA on the Meso Scale Discovery Platform Lab Procedure Manual (September 2024)
Serum samples were processed, stored, and shipped to the Chronic Viral Diseases Branch, Division of High-Consequence Pathogens and Pathology, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA for analysis.
Detailed instructions on specimen collection and processing are discussed in the NHANES Laboratory Procedures Manual (LPM). Vials were stored under appropriate frozen conditions (-20°C) until they were shipped to the National Center for Emerging and Zoonotic Infectious Diseases for testing. The M9ELISA was conducted in the HPV Immunology lab at the Centers for Disease Control and Prevention.
The NHANES quality assurance and quality control (QA/QC) protocols meet the 1988 Clinical Laboratory Improvement Amendments mandates. Detailed QA/QC instructions are discussed in the NHANES LPM.
Mobile Examination Centers (MECs)
Laboratory team performance is monitored using several techniques. NCHS and contract consultants use a structured competency assessment evaluation during visits to evaluate both the quality of the laboratory work and the QC procedures. Each laboratory staff member is observed for equipment operation, specimen collection and preparation; testing procedures and constructive feedback are given to each staff member. Formal retraining sessions are conducted annually to ensure that required skill levels were maintained.
Analytical Laboratories
NHANES uses several methods to monitor the quality of the analyses performed by the contract laboratories. In the MEC, these methods include performing blind split samples collected on “dry run” sessions. In addition, contract laboratories randomly perform repeat testing on 2% of all specimens.
NCHS developed and distributed a quality control protocol for all CDC and contract laboratories, which outlined the use of Westgard rules (Westgard et. al., 1981) when running NHANES specimens. Progress reports containing any problems encountered during shipping or receipt of specimens, summary statistics for each control pool, QC graphs, instrument calibration, reagents, and any special considerations are submitted to NCHS quarterly. The reports are reviewed for trends or shifts in the data. The laboratories are required to explain any identified areas of concern.
The data were reviewed. Incomplete data or improbable values were sent to the performing laboratory for confirmation.
Refer to the 2015-2016 Laboratory Data Overview 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. 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 other analytic issues.
Sample Weights
MEC exam sample weights should be used for analyses.
Demographic and Other Related Variables
The analysis of NHANES 2015-2016 laboratory data must be conducted using the appropriate survey design and demographic variables. The NHANES 2015-2016 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
Two variables are provided for each of these analytes. The variable name ending in “LC” (ex., LBD9M6LC) indicates whether the result was below the limit of quantitation: the value “0” means that the result was at or above the limit of quantitation, “1” indicates that the result was below the limit of quantitation. For analytes with analytic results below the lower limit of quantitation (ex. LBD9M6LC =1), an imputed fill value was placed in the analyte results field. This value is the lower limit of quantitation divided by the square root of 2 (LLOQ/sqrt[2]). The other variable prefixed “LBD” and ended with an “N” (ex., LBD9M6N) provides the analytic result for the analyte.
The lower limit of quantitation (LLOQ, in units) for HPV antibody 6, 11, 16, 18, 31, 33, 45, 52, & 58 are:
VARIABLE | ANALYTE NAME | LLOQ |
---|---|---|
LBD9M6N | HPV 6 (Quantitative) | 2.2 IU/ml |
LBD9M11N | HPV 11 (Quantitative) | 2.6 IU/ml |
LBD9M16N | HPV 16 (Quantitative) | 1.2 IU/ml |
LBD9M18N | HPV 18 (Quantitative) | 0.4 IU/ml |
LBD9M31N | HPV 31 (Quantitative) | 2.2 IU/ml |
LBD9M33N | HPV 33 (Quantitative) | 3.6 IU/ml |
LBD9M45N | HPV 45 (Quantitative) | 1.2 IU/ml |
LBD9M52N | HPV 52 (Quantitative) | 4.3 IU/ml |
LBD9M58N | HPV 58 (Quantitative) | 4.0 IU/ml |
Note: LLOQ – lower limit of quantitation; IU/ml – International Units/milliliter
Serostatus Cut-off Value
The qualitative results for the analytes are provided in variables prefixed “LBX” (ex., LBX9M6). Serostatus cut-off value for a positive result for each HPV analyte was established as below. An antibody concentration below this value is coded as negative and a value equal or above is considered positive.
VARIABLE | ANALYTE NAME | Cut-off Value |
---|---|---|
LBX9M6 | HPV 6 (Qualitative) | 7.6 IU/ml |
LBX9M11 | HPV 11 (Qualitative) | 5.2 IU/ml |
LBX9M16 | HPV 16 (Qualitative) | 1.6 IU/ml |
LBX9M18 | HPV 18 (Qualitative) | 3.5 IU/ml |
LBX9M31 | HPV 31 (Qualitative) | 5.5 IU/ml |
LBX9M33 | HPV 33 (Qualitative) | 6.8 IU/ml |
LBX9M45 | HPV 45 (Qualitative) | 4.2 IU/ml |
LBX9M52 | HPV 52 (Qualitative) | 6.2 IU/ml |
LBX9M58 | HPV 58 (Qualitative) | 12.8 IU/ml |
Note: IU/ml – International Units/milliliter
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1.6 to 28188 | Range of Values | 4252 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
0 | At or above the limit of quantitation | 2916 | 2916 | |
1 | Below the limit of quantitation | 1336 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1.8 to 15990 | Range of Values | 4252 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
0 | At or above the limit of quantitation | 1497 | 1497 | |
1 | Below the limit of quantitation | 2755 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
0.8 to 7404 | Range of Values | 4252 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
0 | At or above the limit of quantitation | 1473 | 1473 | |
1 | Below the limit of quantitation | 2779 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
0.3 to 2808 | Range of Values | 4252 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
0 | At or above the limit of quantitation | 3357 | 3357 | |
1 | Below the limit of quantitation | 895 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1.6 to 1694 | Range of Values | 4252 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
0 | At or above the limit of quantitation | 1592 | 1592 | |
1 | Below the limit of quantitation | 2660 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
2.5 to 1392 | Range of Values | 4252 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
0 | At or above the limit of quantitation | 814 | 814 | |
1 | Below the limit of quantitation | 3438 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
0.8 to 1035 | Range of Values | 4252 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
0 | At or above the limit of quantitation | 1658 | 1658 | |
1 | Below the limit of quantitation | 2594 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
3 to 4590 | Range of Values | 4252 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
0 | At or above the limit of quantitation | 1434 | 1434 | |
1 | Below the limit of quantitation | 2818 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
2.8 to 2584.1 | Range of Values | 4252 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
0 | At or above the limit of quantitation | 1426 | 1426 | |
1 | Below the limit of quantitation | 2826 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | Positive | 1567 | 1567 | |
2 | Negative | 2685 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | Positive | 1089 | 1089 | |
2 | Negative | 3163 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | Positive | 1324 | 1324 | |
2 | Negative | 2928 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | Positive | 1118 | 1118 | |
2 | Negative | 3134 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | Positive | 852 | 852 | |
2 | Negative | 3400 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | Positive | 475 | 475 | |
2 | Negative | 3777 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | Positive | 520 | 520 | |
2 | Negative | 3732 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | Positive | 1073 | 1073 | |
2 | Negative | 3179 | 4252 | |
. | Missing | 346 | 4598 |
Code or Value | Value Description | Count | Cumulative | Skip to Item |
---|---|---|---|---|
1 | Positive | 553 | 553 | |
2 | Negative | 3699 | 4252 | |
. | Missing | 346 | 4598 |