MANDATORY USE OF CONFIRMATION STAGE WITH CHLAMYDIAZYME DURING URINARYSEDIMENT ANALYSIS

Aims-To assess whether false positive results found when the first sta ge Chlamydiazyme test is performed on urinary sediment could be reduce d by using the more specific second stage blocking assay. Methods-Sedi ment from 173 urine samples from patients with suspected urinary tract infection caused by Gram negative bacteria and 23 control urine sampl es were tested using the Chlamydiazyme assay system, which included a blocking assay. Results-A reaction result with the first stage Chlamyd iazyme assay test was seen in 102 (58.9%) of the test urine samples. F irst stage reactivity was not blocked by the Chlamydiazyme confirmator y assay performed on repeat testing. All were correctly identified as true negative (first test false positive) results. Conclusions-Use of a second (specific) blocking assay for the analysis of urinary sedimen t using Chlamydiazyme eliminates false positive results in Gram negati ve urinary tract infections.