Abilities of APTIMA, AMPLICOR, and ProbeTec assays to detect Chlamydia trachomatis and Neisseria gonorrhoeae in PreservCyt ThinPrep Liquid-based Pap samples.
Infections with Chlamydia trachomatis and Neisseria gonorrhoeae are often asymptomatic. Liquid-based Pap (L-Pap) screening may provide samples for testing by commercial assays. Women attending a health clinic or a street youth clinic had a PreservCyt ThinPrep sample and a cervical swab (CS) collected. The L-Pap sample was tested for cytopathology; then 1 ml was transferred to an L-Pap specimen transfer tube for testing by the Gen-Probe APTIMA assays (APTIMA Combo 2 [AC2], APTIMA C. trachomatis [ACT], and APTIMA N. gonorrhoeae [AGC]). The residual L-Pap sample was tested for C. trachomatis and N. gonorrhoeae using Roche AMPLICOR (AMP) and Becton Dickinson ProbeTec (PT). The CS was tested by AC2. A patient was considered infected if two specimens were positive or if a single specimen was positive in two tests. The prevalence of infection was 10% (29/290) for C. trachomatis and 2.4% (7/290) for N. gonorrhoeae. Most of the positive patients had specimens that were reactive in all assays (20/29 for C. trachomatis; 6/7 for N. gonorrhoeae). Four patients had double infections. The sensitivities and specificities of the various tests for the specimens tested were as follows. For C. trachomatis on L-Pap, sensitivity and specificity were 100 and 98.1%, respectively, for ACT, 93.1 and 98.8% for AC2, 86.2 and 91.2% for AMP, and 72.4 and 92.7% for PT. For N. gonorrhoeae on L-Pap, sensitivity and specificity were 100% for both AGC and AC2, 85.7 and 100% for AMP, and 85.7 and 100% for PT. For AC2 with CSs, sensitivity and specificity were 93.1 and 98.5%, respectively, for C. trachomatis, and both were 100% for N. gonorrhoeae. There were significant differences in sensitivity and specificity (P < 0.001). The APTIMA assays were more sensitive and specific than AMP or PT for detecting women's C. trachomatis and/or N. gonorrhoeae infections by testing ThinPrep samples.
Chernesky
M
M
St. Joseph's Healthcare/McMaster University, Toronto, Ontario, Canada. chernesk@mcmaster.ca
Jang
D
D
Portillo
E
E
Chong
S
S
Smieja
M
M
Luinstra
K
K
Petrich
A
A
Macritchie
C
C
Ewert
R
R
Hayhoe
B
B
Sarabia
A
A
Thompson
F
F
D002690:Chlamydia Infections / Q000382:microbiology; D002692:Chlamydia trachomatis / Q000235:genetics / Q000302:isolation & purification*; D005260:Female; D006069:Gonorrhea / Q000382:microbiology; D006801:Humans; D025202:Molecular Diagnostic Techniques; D009344:Neisseria gonorrhoeae / Q000235:genetics / Q000302:isolation & purification*; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D014626:Vaginal Smears
D011933:Reagent Kits, Diagnostic