COMPARISON OF PCR NUCLEIC-ACID HYBRIDIZATION AND EIA FOR THE DETECTION OF CHLAMYDIA-TRACHOMATIS IN DIFFERENT POPULATIONS IN A REGIONAL CENTER

Culture on McCoy cell monolayers has been accepted as the reference me thod for the detection of Chlamydia trachomatis. Recent studies have s hown that polymerase chain reaction (PCR)/nucleic acid hybridization b ased methods have increased sensitivity over culture while still retai ning specificity. In situations where organism viability is of concern , due to factors such as transportation delays, culture is inappropria te. Regional laboratories therefore have not been able to utilize the reference method and have been forced to use less reliable methods. Th e aims of our study were to assess the feasibility of performing PCR t o diagnose infections due to C. trachomatis in a regional laboratory u sing a new commercial kit - AmplicorTM (Roche Molecular Systems, Branc hburg, NJ) and to compare the current enzyme-immunoassay (EIA) based-m ethods used in our laboratory (VIDASTM [bioMerieux Vitek, Hazelwood MO ] and IDEIATM [Novo Nordisk Diagnostics, Cambridge, UK]) against PCR. Thirteen positive AmplicorTM specimens were found in 267 urine specime ns collected from asymptomatic adolescent males and females. All 13 we re confirmed positive using major outer membrane protein gene PCR (MOM P). VIDASTM and IDEIATM showed 100% correlation to each other but only detected 5/13 positives. Of 140 consecutive patients attending the re gional sexual health clinic, 13 were AmplicorTM positive, 11/13 MOMP p ositive and 10/13 positive by VIDASTM. Five of 254 patients attending the hospital antenatal clinic were positive by AmplicorTM, all being c onfirmed by MOMP. No PCR inhibition was detected in a random sample of 100 varied negative AmplicorTM tests using a modification of the Ampl icorTM kit. No contamination was experienced. The AmplicorTM kit was s hown to be suitable for use in the routine clinical laboratory with mi nimal disruption to workflow. For regional laboratories this kit shoul d provide more accurate results than EIA based methods, particularly i n the detection of asymptomatic persons.