Table of Contents

Component Description

Sexually transmitted infections caused by Chlamydia trachomatis may lead to pelvic inflammatory disease, ectopic pregnancy, infertility, and chronic pelvic pain in women. They are associated with increased risk of HIV transmission. Pregnant women may transmit infection to their newborn causing serious medical complications. At present there are no reliable estimates on the prevalence of chlamydial and gonococcal infection in the general population of the United States.

NHANES offers an opportunity to assess the prevalence of chlamydia and gonococcal infection in the general population and to monitor trends in prevalence as prevention programs are established and expanded.

Eligible Sample

Participants aged 14-39 years were tested. The public data file includes data for persons 18-39 years of age. Please see Analytic Notes about the release of data for adolescents 14-17 years of age.

Description of Laboratory Methodology

Urinary Chlamydia and Urinary Gonorrhea

The BDProbeTec CT Chlamydia trachomatis and Neisseria gonorrhoeae Amplified DNA Assays are based on the simultaneous amplification and detection of target DNA using amplification primers and a fluorescent labeled detector probe. The Strand Displacement Amplification (SDA) reagents are dried in two separate disposable microwell strips. The processed sample is added to the Priming Microwell which contains the amplification primers, fluorescent labeled detector probe, and other reagents necessary for amplification. After incubation, the reaction mixture is transferred to the Amplification Microwell, which contains two enzymes (a DNA polymerase and a restriction endonuclease) necessary for SDA. The Amplification Microwells are sealed to prevent contamination and then incubated in a thermally controlled fluorescent reader which monitors each reaction for the generation of amplified products. The presence or absence of C. trachomatis and N. gonorrhoeae is determined by relating the BDProbeTec ET MOTA (Method Other Than Acceleration) scores for the sample to pre-determined cutoff values. The MOTA score is a metric used to assess the magnitude of signal generated as a result of the reaction.

Data Processing and Editing

Urine specimens were processed, stored and shipped to the Division of AIDS, STD, and TB Laboratory Research, National Center for Infectious Diseases, National Centers for Disease Control and Prevention for analysis. Detailed specimen collection and processing instructions are discussed in the NHANES Laboratory/Medical Technologists Procedures Manual (LPM). Read the LABDOC file for detailed data processing and editing protocols. The analytical methods are described in the Description of the Laboratory Methodology section.

Laboratory Quality Assurance and Monitoring

The NHANES quality control and quality assurance protocols (QA/QC) meet the 1988 Clinical Laboratory Improvement Act mandates. Detailed quality control and quality assurance instructions are discussed in the NHANES Laboratory/Medical Technologists Procedures Manual (LPM). Read the LABDOC file for detailed QA/QC protocols.

Analytic Notes

The public release data file includes urinary chlamydia data for participants aged 18–39. Data for youth aged 14–17 years are available through the NCHS Research Data Center (RDC).

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 14 YEARS - 17 YEARS

URXUCL - Urinary Chlamydia

Variable Name:
URXUCL
SAS Label:
Urinary Chlamydia
English Text:
Urinary Chlamydia
Target:
Both males and females 14 YEARS - 17 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Positive 19 19
2 Negative 1037 1056
3 Indeterminate 0 1056
. Missing 41 1097

URXUGC - Urinary Gonorrhea

Variable Name:
URXUGC
SAS Label:
Urinary Gonorrhea
English Text:
Urinary Gonorrhea
Target:
Both males and females 14 YEARS - 17 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1 Positive 5 5
2 Negative 1051 1056
3 Indeterminate 0 1056
. Missing 41 1097