title: Pooling cervical swabs and testing by ligase chain reaction are accurate and cost-saving strategies for diagnosis of Chlamydia trachomatis.
abstract: Specimen pooling to achieve efficiency when testing urine specimens for Chlamydia trachomatis nucleic acids has been suggested. We pooled endocervical swabs from 1,288 women and also tested individual swabs by ligase chain reaction (LCR). Out of 53 positive specimens, pools of 4 or 8 specimens missed two positives, providing 96.2% accuracy compared to individual test results. Dilution and positive-control spiking experiments showed that negative specimens with inhibitors of LCR in the pool reduced the signal. Conversely, two extra positives, detected only through pooling, were negative by individual testing but became positive after storage, suggesting that fresh positive specimens with labile inhibitors may be positive in a pool because of dilution of inhibitors. For this population of women with a 4% prevalence of C. trachomatis infection, substantial savings in cost of reagents (55 to 63%) and technologist time (50 to 63%) made pooling strategies a desirable alternative to individual testing.
authors.affiliation: Gamma-Dynacare Medical Laboratories, Brampton, Ontario, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Kapala
authors.forename: D
authors.initials: D
authors.lastname: Copes
authors.forename: A
authors.initials: A
authors.lastname: Sproston
authors.forename: J
authors.initials: J
authors.lastname: Patel
authors.forename: D
authors.initials: D
authors.lastname: Jang
authors.forename: A
authors.initials: A
authors.lastname: Petrich
authors.forename: J
authors.initials: J
authors.lastname: Mahony
authors.forename: K
authors.initials: K
authors.lastname: Biers
authors.forename: M
authors.initials: M
authors.lastname: Chernesky
mesh_terms: D002584:Cervix Uteri / Q000382:microbiology; D002690:Chlamydia Infections / Q000175:diagnosis* / Q000382:microbiology; D002692:Chlamydia trachomatis / Q000235:genetics / Q000302:isolation & purification*; D011088:DNA Ligases; D005260:Female; D005784:Gene Amplification; D006801:Humans; D011933:Reagent Kits, Diagnostic / Q000191:economics; D013048:Specimen Handling / Q000191:economics*; D013997:Time Factors
chemical_list: D011933:Reagent Kits, Diagnostic; D011088:DNA Ligases