MMWR: Screening Tests to Detect Chlamydia trachomatis and Neisseria gonorrhoeae Infections -- 2002

This monograph presents guidelines to (1) assist laboratorians, clinicians, and managers select screening tests for C. trachomatis or N. gonorrhoeae from the multiple available tests; (2) establish standard operating procedures for collecting, processing, and analyzing specimens; and (3) interpret test results for laboratory reporting, counseling, and treating patients. The monograph reviews the technologies available for laboratory diagnosis of c. trachomatis and N. gonorrhoeae. The technologies are subdivided into those that are designed for batch testing in a laboratory, or point-of-care testing as single tests or a limited number of tests performed while patients await results. Laboratory-based tests include culture, nucleic acid amplification tests (NAATs), nucleic acid hybridization and transformation tests, EIAs, and DFA tests. Because of the increased costs of NAATs certain labs are modifying manufacturer’s procedures to improve test sensitivity without incurring the full cost associated with screening with a NAAT. Such approaches addressed in these guidelines are pooling of specimens before testing with a NAAT and additional testing of specimens whose non-NAAT test result is within a gray zone. The monograph also addresses the need for additional testing after a positive screening test to improve the specificity of a final diagnosis.