Table of Contents

Component Description

Human papillomavirus (HPV) infection is the most common sexually transmitted infection in the United States. Cervical infection with certain types of HPV is causally associated with cervical cancer in women. No national surveillance system exists to measure the full burden of HPV infection, and no reliable national population estimate of HPV exists. NHANES offers a unique opportunity to assess the prevalence of HPV infection in the general population.

Reducing the prevalence of HPV infection is a Developmental Healthy People 2010 objective: “Reducing the number of new HPV cases can help minimize the overall number of cases of high risk subtypes associated with cervical cancer in females ...” Two HPV vaccines are licensed, and knowledge of the national prevalence of HPV infection is critical for planning vaccination strategies and monitoring the impact of vaccination in the United States.

Eligible Sample

All participants aged 18 to 59 years were eligible.

Description of Laboratory Methodology

Competitive Luminex Immunoassay of Antibodies to Neutralizing Epitopes on HPV 6, 11, 16 and 18 (4-plex CLIA) L1-Virus-Like Particles (VLPs)

This method uses the Luminex platform to simultaneously assay antibodies to HPV 6, 11, 16 and 18. Type-specific antibodies of any Ig class are detected by competing with and blocking the binding of fluorescently tagged neutralizing monoclonal antibody from VLP-coated microspheres.

Laboratory Method Files

HPV Serum 4-Multiplex Luminex Laboratory Procedure Manual (December 2013)

Laboratory Quality Assurance and Monitoring

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). Serum 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 NHANES quality assurance and quality control (QA/QC) protocols meet the 1988 Clinical Laboratory Improvement Act 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 quality-control 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.

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.

Data Processing and Editing

The data were reviewed. Incomplete data or improbable values were sent to the performing laboratory for confirmation.

Analytic Notes

Refer to the 2007-2008 Laboratory Data Overview for general information on NHANES laboratory data.

Sample Weights

MEC exam sample weights should be used for analyses.

Demographic and Other Related Variables

The analysis of NHANES laboratory data must be conducted using the appropriate survey design and demographic variables. The NHANES 2007-2008 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).

The Questionnaire data files contain socio-economic data, health indicators, and other related information collected during household interviews. Certain sensitive data on participants under 18 years of age (e.g., HPV typing results, sexual behavior variables) are not included in the public use files. These data may be requested as described in the NHANES guidelines.

Serum

Competitive Luminex Immunoassay for HPV 6, 11, 16, 18 (4-plex CLIA) established the serostatus cut-off values for a positive result for each HPV type in the assay as listed below. A final titer below this value is negative and a value equal or above is considered positive.

Sero-Status Cutoff(mMU/mL): HPV6=20, HPV11=16, HPV16=20, HPV18=24.

Detection Limits

If data is qualitative, the use of lower limits of detection (LLODs) is not applicable.

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 18 YEARS - 59 YEARS

LBX06 - HPV 06 result

Variable Name:
LBX06
SAS Label:
HPV 06 result
English Text:
HPV 06 result
Target:
Both males and females 18 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Positive 695 695
2 Negative 2935 3630
. Missing 320 3950

LBX11 - HPV 11 result

Variable Name:
LBX11
SAS Label:
HPV 11 result
English Text:
HPV 11 result
Target:
Both males and females 18 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Positive 207 207
2 Negative 3423 3630
. Missing 320 3950

LBX16 - HPV 16 result

Variable Name:
LBX16
SAS Label:
HPV 16 result
English Text:
HPV 16 result
Target:
Both males and females 18 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Positive 461 461
2 Negative 3169 3630
. Missing 320 3950

LBX18 - HPV 18 result

Variable Name:
LBX18
SAS Label:
HPV 18 result
English Text:
HPV 18 result
Target:
Both males and females 18 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Positive 212 212
2 Negative 3418 3630
. Missing 320 3950