Chlamydia/GC Detection by Aptima
TECHNICAL UPDATE

DESCRIPTION/BACKGROUND INFORMATION:

Chlamydia trachomatis (CT) and Neisseria gonorrhea (NG) are two of the most common sexually transmitted diseases (STD) in the United States and worldwide. They cause a wide clinical spectrum of disease, including cervicitis, pelvic inflammatory disease, and salpingitis. Each may cause asymptomatic infection, compounding the problem of diagnosis and contributing to the spread of disease. Up to 10% of sexually active asymptomatic males and 3% of sexually active asymptomatic females are infected with Chlamydia trachomatis. 60%-70% of vaginally delivered infants of infected mothers can become infected, possibly resulting in conjunctivitis (80% of infected infants may develop conjunctivitis if not given prophylaxis) or pneumonitis (20% of infected infants). Chlamydia trachomatis infections often give nonspecific symptoms or are totally asymptomatic, complicating diagnosis and enabling further spread of disease. Chlamydial salpingitis is a common cause of infertility in females, even if asymptomatic.

CLINICAL APPLICATION:

The application of sensitive and specific screening methods for the diagnosis of CT and GC is an important tool for controlling the spread of these organisms and reducing the serious complications of untreated disease. Nucleic acid amplification tests (NAAT) have consistently exceeded the sensitivities of non-NAAT methods (direct probe, EIA, culture) in the detection of these organisms. The CDC, therefore, recommends use of a NAAT to screen for genitourinary infections with Chlamydia trachomatis and/or Neisseria gonorrhea. The GEN-PROBE APTIMA Combo 2 Assay utilizes the technology of transcription mediated amplification (TMA) to amplify C. trachomatis and N. gonorrhea ribosomal RNA (rRNA) for the qualitative detection of these organisms

The sensitivity of Gen-Probe's test has been shown to be superior to culture and direct specimen tests and is the only assay with urine specimen sensitivity equivalent to swab specimen.

SPECIMEN:

The GEN-PROBE APTIMA Combo 2 Assay is designed to detect the presence of C. trachomatis and N. gonorrhea in endocervical and male urethral specimens, and in female and male urine specimens. Only the swabs and the specimen transport tubes contained in the APTIMA Combo 2 Assay Unisex Swab Specimen Collection Kit for Endocervical and Urethral Swab Specimens can be used to collect patient swab specimens. A unisex swab is used for both male and female specimens. Swab specimens must be transported to the laboratory in the swab specimen transport medium and tube.

TEST NAME & NUMBER:

• 1130 GC Aptima
• 1131 Chlamydia Aptima
• 1132 Chlamydia/GC Aptima

REFERENCES:

1. Warren, Dwyer, Plackett, Pettit, Rizvi, and Baker, Comparative Evaluation of Detection Assays for Chlamydia trachomatis, Journal of Clinical Microbiology, June 1993. p.1663-1666.
2. Eng, TR et al. Prevention of sexually transmitted diseases. A model for overcoming barriers between managed care and public health. Am J Prev Med. 1999.16;60
3. Hale, Melton, Lewis, and Willis, Evaluation of PACE 2 Neisseria gonorrhoeae Assay by Three Public Health Laboratories, Journal of Clinical Microbiology, Feb 1993. p.451-453.
4. Newhall, DeLisle, et al., Head-to-Head Evaluation of Five Different Non-Culture Chlamydia Tests Relative to a Quality-Assured Culture Standard.
5. Centers for Disease Control and Prevention. Screening tests to detect Chlamydia trachomatis and Neisseria gonorrhoeae infections, 2002. MMWR 2002; 51(RR-15):1-39.