Evaluation of Laboratory Testing Methods for Chlamydia trachomatis Infection in the Era of Nucleic Acid Amplification

Abstract

Diagnostic tests presently available for Chlamydia trachomatis have widely varying performance characteristics. To assess evolving laboratory testing practices since the introduction of nucleic acid amplification tests (NAAT), we surveyed laboratories in Washington State about their testing practices in 1998 and compared our findings to a similar survey conducted in 1995. Laboratory directors of 61 (87%) of 70 laboratories performing chlamydial tests in 1998 returned a survey. Between 1995 and 1998, 36 laboratories discontinued chlamydial testing, and the total number of laboratories performing tests in the state decreased from 92 to 70, a 24% decline. Of the 36 laboratories that discontinued testing, 25 (69%) had previously used rapid tests. While no laboratory routinely used NAAT in 1995, ligase chain reaction (LCR) was used in 23% of laboratories in 1998 and accounted for 113,624 (36%) of the 318,133 tests performed that year. Among the remaining 204,509 tests performed in 1998, other tests employed included DNA probe (29%), enzyme immunoassay (20%), culture (12%), direct fluorescent antibody assays (3%), and rapid tests (<1%). The majority (65%) of tests performed in 1998 using technologies other than LCR or culture were done in laboratories that did more than 10,000 tests. Cost and loss of revenue to laboratories were the most frequently cited reasons for not adopting NAAT. We conclude that in Washington State, NAAT have been rapidly adopted in larger laboratories, but most patients are still tested with much less sensitive technologies. Financial constraints represent the major barrier to more widespread use of DNA amplification tests.

Current issues in screening for Chlamydia trachomatis

“…One problem is that many clinical and public health laboratories fail to implement improved screening methods. A survey in 1999, for example, found that only one third of laboratories were using recently developed testing methods [46]. A second problem is the lack of organizational priority for chlamydial screening among managed care organizations [47].…”

Novel Fluorescent Ligase Detection Reaction and Flow Cytometric Analysis of SYT-SSX Fusions in Synovial Sarcoma

“…21,22 In the clinical setting, LCR has been used in the detection of infectious disease pathogens, including Chlamydia trachomatis and Mycobacterium tuberculosis. [23][24][25][26] Eggerding and co-workers 27,28 pioneered the use of a multiplex, one-sided (one-target strand) oligonucleotide ligation assay (OLA), either simultaneous with, or following PCR to identify CFTR and RAS gene mutations. These studies also used fluorescentlylabeled oligonucleotides to detect specific wild-type or mutant sequences by differences in size and fluores- These results were 100% concordant with f-LDR data (see Figure 3 and Table 3) and were further confirmed by PCR product sequencing (see Figure 5).…”

Evaluation of the Digene Hybrid Capture II Assay with the Rapid Capture System for Detection ofChlamydia trachomatisandNeisseria gonorrhoeae

“…Although these assays have demonstrated excellent sensitivities and specificities in clinical trials (6,28,29,30), they require extreme technical precision in order to achieve maximum performance (18,22,28). With the assays available at present, this translates into labor-intensive diagnostic methods, often with low-throughput capacity (2,3,16). In this study we evaluated a semiautomated system application of the signal amplification-based Hybrid Capture 2 CT/GC (HC2) assay that allows testing of 352 samples for both C. trachomatis and N. gonorrhoeae during an 8-h shift.…”