Duplicate endocervical swabs were collected for detection of Chlamydia trachomatis by PCR (Roche Diagnostics). One swab was swirled in Specimen Transport Medium (Roche) for PCR testing and discarded. A saline aliquot from the other specimen, sent as a dry swab to the laboratory, was Papanicolaou stained to determine specimen adequacy, and the remainder was PCR tested. Significantly more (24%) PCR-positive results (118 versus 95; P < 0.001) were obtained with the dry specimens than with the swirled specimens when first tested. In addition, PCR-positive results were obtained with 107 (10.6%) of 1,007 microscopically adequate specimens but with only 3 (0.9%) of 341 inadequate specimens (P < 0.001).

The simple, rapid, two-step Diff-Quik stain procedure (Baxter Diagnostics) was compared with the Papanicolaou stain for microscopic determination of endocervical specimen quality. Results from 230 (98.7%) of 233 specimens stained by both methods indicated agreement between the two staining methods for detection of the endocervical cells or erythrocytes indicating specimen adequacy. By using the Amplicor Chlamydia trachomatis Test (Roche Diagnostic Systems) to detect C. trachomatis and the Diff-Quik stain to assess specimen adequacy, PCR-positive results were obtained from 147 (9.1%) of 1,615 microscopically adequate specimens but from only 13 (2.2%) of the 583 inadequate specimens (P < 0.001).

Endocervical swab and cytobrush specimens from 1,301 symptomatic women were microscopically analyzed for adequacy and tested using Chlamydiazyme (CZ) (Abbott Laboratories). When the swab specimen was collected first, blocking antibody-confirmed CZ-positive results were obtained from 48 (8.0%) of 599 patients, 42 (87.5%) from swabs and 46 (95.8%) from cytobrushes (not significant). When the swab specimen was collected second, confirmed CZ-positive results were obtained from 46 (6.6%) of 702 patients, 44 (95.6%) from swabs and 41 (89.1%) from cytobrushes (not significant). Cytobrushes offered no significant advantage over swabs for CZ detection of Chiamydia trachomatis.