Chlamydia trachomatis

Chlamydia trachomatis infection is the most common notifiable disease in the United States with >1.3 million infections reported to CDC in 2010 (1). The majority of persons with C. trachomatis infection are not aware of their infection because they do not have symptoms that would prompt them to seek medical care (2). Consequently, screening is necessary to identify and treat this infection. Direct medical costs of C. trachomatis infections were estimated at $516.7 million in 2008 (2012 dollars) (3). The direct costs associated with C. trachomatis infections and their sequelae have decreased in recent years as sequelae have been managed in a less-costly manner and ectopic pregnancies have been increasingly managed medically (4). Also of importance are the tangible costs, including the lost productivity, and the intangible costs, including psychological and emotional injury caused by infertility and ectopic pregnancy (5).

Untreated C. trachomatis infections can lead to serious complications. In older observational treatment studies, up to 30% of women with untreated C. trachomatis infections developed pelvic inflammatory disease (PID) (6,7). Of these women, the majority had symptoms that were too mild or nonspecific to cause them to seek medical treatment. Regardless of symptom intensity, the consequences of PID are severe. Left untreated, 20% of those with symptomatic PID might become infertile; 18% will experience debilitating, chronic pelvic pain; and 9% will have a life-threatening tubal pregnancy (8). The importance of subclinical PID became apparent with observations that most of the women with tubal factor infertility or ectopic pregnancy who had serologic evidence of chlamydial infection apparently had no history of PID (9,10). C. trachomatis infection during pregnancy might lead to infant conjunctivitis and pneumonia and maternal postpartum endometritis (11). Among men, urethritis is the most common illness resulting from C. trachomatis infection. Complications (e.g., epididymitis) affect a minority of infected men and rarely result in reproductive health sequelae (12).

C. trachomatis infections of the rectum can result from unprotected anal intercourse and are typically asymptomatic but might progress to proctocolitis (13,14). Ocular infections can result in conjunctivitis in neonates and adults (15). Sexually acquired reactive arthritis also has been reported as a possible consequence of C. trachomatis infection (16).

Neisseria gonorrhoeae

N. gonorrhoeae infections are the second most common notifiable communicable disease in the United States with 309,341 cases being reported to CDC in 2010 (1). Gonococcal infections tend to cause a stronger inflammatory response than C. trachomatis but are typically asymptomatic in women until complications such as PID develop (17). In men, the majority of urethral infections cause urethritis with painful urination and, less commonly, epididymitis or disseminated gonococcal infection (17).

Subsets of men who have sex with men (MSM) engage in risky sexual behaviors (e.g., having sex with multiple, anonymous partners and unprotected oral and rectal sex), often leading to infections at these extragenital sites. MSM might have a high prevalence of sexually transmitted infections especially at these extragenital sites, which can be a public health problem because of the potential for enhancing HIV transmission (18). CDC recommends routine laboratory screening of genital and extragenital sites for all sexually active MSM at risk for infection (19).

Purpose of This Report

This report updates CDC’s 2002 recommendations regarding screening tests to detect C. trachomatis and N. gonorrhoeae infections (20) and provides new recommendations regarding optimal specimen types, the use of tests to detect rectal and oropharyngeal C. trachomatis and N. gonorrhoeae infections, and information regarding when supplemental testing is indicated (Box 1). These recommendations are intended for use by clinical laboratory directors, laboratory staff, clinicians, and disease control personnel who must choose among the multiple available tests, establish standard operating procedures for collecting and processing specimens, interpret test results for laboratory reporting, and counsel and treat patients.

BOX 1. Summary of recommendations

  • Nucleic acid amplification tests (NAATs) that are cleared by the Food and Drug Administration (FDA) are recommended for detection of genital tract infections caused by Chlamydia trachomatis and Neisseria gonorrhoeae infections in men and women with and without symptoms. For detecting these infections of the genital tract, optimal specimen types for NAATs are vaginal swabs from women and first catch urine from men. Older nonculture tests and non-NAATs have inferior sensitivity and specificity characteristics and no longer are recommended.
  • NAATs have not been cleared by FDA for the detection of rectal and oropharyngeal infections caused by C. trachomatis and N. gonorrhoeae. CDC is recommending NAATs to test for these extragenital infections based on increased sensitivity, ease of specimen transport and processing. Because these specimen types have not been cleared by FDA for use with NAATs, laboratories must establish performance specifications when using these specimens to meet Clinical Laboratory Improvement Amendments (CLIA) regulatory requirements and local or state regulations as applicable prior to reporting results for patient management. Positive reactions with nongonococcal Neisseria species have been reported with some NAATs, particularly with oropharyngeal specimens. Alternate target testing using NAATs without reported crossreactivity might be needed to avoid false positive gonorrhea results when using these tests with these specimens.
  • Routine repeat testing of NAAT-positive genital tract specimens is not recommended because the practice does not improve the positive predictive value of the test.
  • Laboratory interpretation of test results should be consistent with product inserts for FDA-cleared tests or have met all federal and state regulations for a modified procedure if the laboratory has changed the cutoff values or testing algorithm. This approach provides the most appropriate information to the clinician, who is ultimately responsible for assessing test results to guide patient and partner management.
  • N. gonorrhoeae culture capacity is still needed for evaluating suspected cases of treatment failure and monitoring antimicrobial susceptibility.
  • C. trachomatis and N. gonorrhoeae culture capacity might still be needed in instances of child sexual assault in boys and extragenital infections in girls.