Steven G Badman1, Sara F E Bell2, Judith A Dean2, Jime Lemoire3, Luke Coffey3, Joseph Debattista4, Andrew M Redmond5, Owain D Williams2, Charles F Gilks2, David M Whiley6. 1. The Kirby Institute, Level 6, Wallace Wurth Building, High Street, UNSW Sydney, Randwick, NSW 2032, Australia; and Corresponding author. Email: sbadman@kirby.unsw.edu.au. 2. School of Public Health, The University of Queensland, 288 Herston Road, Herston, Qld 4006, Australia. 3. RAPID, Queensland Positive People, 21 Manilla Street, East Brisbane, Qld 4169, Australia. 4. Metro North Public Health Unit, Bryden Street, Windsor, Qld 4030, Australia. 5. RAPID, Queensland Positive People, 21 Manilla Street, East Brisbane, Qld 4169, Australia; and Infectious Diseases Services, Royal Brisbane and Women's Hospital, Herston, Qld 4029, Australia. 6. Centre for Clinical Research, The University of Queensland, Building 71/918, Royal Brisbane and Women's Hospital Campus, Herston, Qld 4029, Australia; and Pathology Queensland, Level 4, Block 7, Royal Brisbane and Women's Hospital, Herston, Qld 4006, Australia.
Abstract
Background The aim of this study was to compare the performance of pooled self-collected urogenital, pharyngeal and anorectal specimens to that of individual specimen results for the molecular detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) near the point of care (POC) for diagnostic sensitivity. METHODS: Clients (mostly men who have sex with men) attending an urban community testing service and three sex-on-premises venues in Brisbane, Australia, were offered CT and NG testing by trained lay providers. Participants provided three self-collected specimens (urine, pharyngeal and rectal) for testing by GeneXpert (Cepheid, Sunnyvale, CA, USA). If any of the individual specimens from a participant were positive, all three specimens were pooled and retested. RESULTS: Of the 388 participants who provided three individual anatomical specimens, 76 (19.6%) were found to be positive for CT and/or NG at one or more sites. The pooling approach failed to detect five CT rectal and four NG pharyngeal infections. The overall performance (sensitivity) of the pooling approach compared with individual specimen testing and Cohen's κ were 90.0% and 0.86 respectively for CT and 89.7% and 0.89 respectively for NG. CONCLUSIONS: Reduced sensitivity was observed when using pooled specimens for the detection of CT and NG using GeneXpert near the POC, similar to results reported in laboratory-based CT and NG pooling studies. These data suggest specimen pooling is feasible near to the POC, potentially saving time and costs when screening at-risk populations for CT and NG. Our data also suggest a reduction in pooled urine could improve overall test sensitivity.
Background The aim of this study was to compare the performance of pooled self-collected urogenital, pharyngeal and anorectal specimens to that of individual specimen results for the molecular detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) near the point of care (POC) for diagnostic sensitivity. METHODS: Clients (mostly men who have sex with men) attending an urban community testing service and three sex-on-premises venues in Brisbane, Australia, were offered CT and NG testing by trained lay providers. Participants provided three self-collected specimens (urine, pharyngeal and rectal) for testing by GeneXpert (Cepheid, Sunnyvale, CA, USA). If any of the individual specimens from a participant were positive, all three specimens were pooled and retested. RESULTS: Of the 388 participants who provided three individual anatomical specimens, 76 (19.6%) were found to be positive for CT and/or NG at one or more sites. The pooling approach failed to detect five CT rectal and four NG pharyngeal infections. The overall performance (sensitivity) of the pooling approach compared with individual specimen testing and Cohen's κ were 90.0% and 0.86 respectively for CT and 89.7% and 0.89 respectively for NG. CONCLUSIONS: Reduced sensitivity was observed when using pooled specimens for the detection of CT and NG using GeneXpert near the POC, similar to results reported in laboratory-based CT and NG pooling studies. These data suggest specimen pooling is feasible near to the POC, potentially saving time and costs when screening at-risk populations for CT and NG. Our data also suggest a reduction in pooled urine could improve overall test sensitivity.
Authors: Lily Aboud; Yangqi Xu; Eric P F Chow; Teodora Wi; Rachel Baggaley; Maeve B Mello; Christopher K Fairley; Jason J Ong Journal: BMC Med Date: 2021-11-25 Impact factor: 8.775