Evaluation of a new amplified enzyme immunoassay (EIA) for the detection of Chlamydia trachomatis in male urine, female endocervical swab, and patient obtained vaginal swab specimens

Aims-To compare the performance of a new generation dual amplified enzyme i mmunoassay (EIA) with a molecular method for the diagnosis of Chlamydia tra chomatis, using a range of urogenital samples, and to assess the reliabilit y of testing self collected vaginal specimens compared with clinician colle cted vaginal specimens. Methods-Two population groups were tested. For the first population group, first void urine samples were collected from 193 male patients with urethri tis, and endocervical swabs were collected from 187 high risk commercial se x workers. All urine and endocervical specimens were tested by a convention al assay (IDEIA chlamydia), a new generation amplified immunoassay (IDEIA P CE chlamydia), and the Amplicor polymerase chain reaction (PCR). Discrepant results obtained among the three sample types were confirmed using a neste d PCR test with a different plasmid target region. For the second populatio n group, four swab specimens, including one patient obtained vaginal swab, two clinician obtained endocervical swabs, and one clinician obtained vagin al swab, were collected from 91 high risk sex workers. Self collected and c linician collected vaginal swabs were tested by IDEIA PCE chlamydia. Clinic ian obtained endocervical swabs were assayed by IDEIA PCE chlamydia and Amp licor PCR. Results-The performance of the IDEIA PCE chlamydia test was comparable to t hat of the Amplicor PCR test when male urine and female endocervical swab s pecimens were analysed. The relative sensitivities of IDEIA, IDEIA PCE, and Amplicor PCR on male first void urine specimens were 79.3%, 91.4%, and 100 %, respectively. The relative sensitivities of the three tests on female en docervical specimens were 85.0%, 95.0%, and 100%, respectively. The positiv ity rates for patient collected vaginal specimens and clinician collected v aginal specimens by IDEIA PCE were 25.2% and 23.1%, respectively, whereas t hose for clinician collected endocervical swabs by PCR and IDEIA PCE were b oth 27.5%. Conclusions-IDEIA PCE chlamydia is a lower cost but sensitive alternative t est to PCR for testing male urine samples and female endocervical swabs. In addition, self collected or clinician collected vaginal specimens tested b y IDEIA PCE chlamydia are a reliable alternative to analysing endocervical specimens.