Sequential Cervical Specimens and the Isolation of Chlamydia trachomatis

Abstract

For 260 consecutive patient visits by women to a clinic for sexually transmitted diseases, 4 cervical specimens were cultured in duplicate for detection of C. trachomatis. A total of 61 positive results were detected by at least 1 of the 4 specimens; the first 2 specimens detected 67-69% and the last two 80-82% of the 61 positives. The difference in these isolation rates is statistically significant (P = 0.003). Duplicate cultures of the same specimen did not significantly increase detection rates. A combination of 2 specimens could increase the number detected by 44.7% beyond the results of a single-specimen culture. Contamination rates were higher for the first 2 speicmens. Routine cleaning of the cervical canal with a swab before the taking of specimens should reduce contamination and increase the probability of obtaining infected cells when they are present.