Multisite pooling study using ligase chain reaction in screening for genital Chlamydia trachomatis infections.
BACKGROUND
Ligase chain reaction (LCR), a nucleic acid amplification assay, is a highly specific and sensitive test for detecting Chlamydia trachomatis in cervical and urethral swabs as well as first-void urine specimens.


OBJECTIVE
To examine the suitability of using the LCR test to detect C trachomatis in pooled cervical specimens.


METHODS
The performance of LCR in pooled specimens was compared with individual specimen testing at six laboratories using 3,170 cervical swab specimens randomly selected from specimens received for routine testing in the participating laboratories. These samples then were combined consecutively into 634 pools of 5 specimens and 317 pools of 10 specimens. A reduced sample to cutoff ratio of 0.2 or more was used for the pooled specimens.


RESULTS
Of the 188 positive specimens (98.9%), 186 were identified when single specimens were analyzed. When pools of 5 or 10 specimens were evaluated, 99.5% and 98.9% of the positive swabs, respectively, were identified correctly. Two positive specimens were detected only through pooling.


CONCLUSIONS
Pooling samples for detection of C trachomatis by LCR is sensitive and specific. Depending on the prevalence of infection (positivity), LCR testing may result in cost savings, as compared with individual testing of specimens.
Clark
A M
AM
University of Washington, Seattle, Washington, USA.
Steece
R
R
Crouse
K
K
Campbell
J
J
Zanto
S
S
Kartchner
D
D
Mottice
S
S
Pettit
D
D
D002584:Cervix Uteri / Q000382:microbiology*; D002690:Chlamydia Infections / Q000175:diagnosis* / Q000453:epidemiology; D002692:Chlamydia trachomatis / Q000235:genetics / Q000302:isolation & purification*; D017046:Cost Savings; D011088:DNA Ligases; D004269:DNA, Bacterial / Q000302:isolation & purification; D005260:Female; D006801:Humans; D022521:Ligase Chain Reaction / Q000191:economics / Q000379:methods*; D015995:Prevalence; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000191:economics / Q000379:methods
D004269:DNA, Bacterial; D011088:DNA Ligases